ralphmelton: (apple)
In February, I posted about my preliminary results with Virulent Strain. After 100 games with four players and five Epidemics with Virulent Strain, my win rate was nearly the same as without Virulent Strain. Was this a lucky streak, or a sign of something else?

I've now played 500 games of 4P5EV. My win rate for 500 games has been 84.0% +/- 3.2%; my win rate for 586 games of 4P5E without Virulent Strain was 84.1% +/- 3.0%.
Some times I look at stats and think that with some more games to narrow the confidence intervals, it might develop into a statistically significant difference. This is not one of those times. To my eye, these stats give no basis for any belief that I win less often with Virulent Strain than without.

But it's obvious that Virulent Strain is harder. (Obvious does not necessarily mean true.) The Virulent Epidemics add ways to fail and don't add ways to succeed.

So maybe Virulent Strain turns easy games into hard games? Not really.
Percentage of easy games: 37.5% +/- 3.9% without Virulent Strain vs. 39.2% +/- 4.3% with Virulent Strain.

Maybe Virulent Strain makes it harder to get Eradications?
For Eradications per successful game: 0.52 +/- 0.06 for 4P5E vs. 0.83 +/- 0.08 for 4P5EV. That's a statistically significant difference of more Eradications with Virulent Strain.

Down at the nigh-anecdotal end of the scale, I got 4 four-Eradication games in 500 games of 4P5EV, compared to none in 586 games of 4P5E.

In my last post about Virulent Strain, I described three possible explanations:
1. I've been having a lucky streak, and am likely to get slapped down soon. This is the most likely possibility.
2. Over the thousand-plus games I've played since my 4P5E games, I've honed my Pandemic skills a bit.
3. The actual increase in difficulty from Virulent Strain is much smaller than it seems.

The 'lucky streak' hypothesis is less plausible now after 500 games.

The 'I've improved my skills' hypothesis has some appeal. I'd like to think that I could improve my skills incrementally over a thousand games, and I can think of ways that I've improved my skills.

And there's a point in favor that Virulent Strain does cause me to lose some games, so I must be making it up somehow. Here's some additional data about how much difficulty Virulent Strain adds:
After the first 100 games, I started recording games in which I felt afterward that I had lost because of Virulent Strain. This is necessarily subjective, and some of the games that I lost because of Virulent Strain would have turned out to be losses even if I had not been playing with Virulent Strain. But with those qualifications, I recorded 21 games out of 400 lost due to Virulent Strain, or about 5.25% of those games. In 3 of those games, I recorded that I thought I would have lost anyway. But still, that suggests that Virulent Strain was the difference between failure and victory in at least 2 or 3% of my games.
But the final victory percentage was almost identical, so I must be making up those games - which seems to suggest an improved skill.

But here's the counterargument: if we hypothesize that I improved my Pandemic skills while playing 500 games of 3P5E and 700 games of 5P5E. It seems obvious (again, not the same as true) that if I improved while playing 5P5E, I would particularly improve at 5P5E. Although I have not done a rigorous analysis, I did not notice any improvement at my win rate with 5P5E over the course of those games - my overall win rate drifted slightly down as I played.

The data shows pretty clearly that with four players and five Epidemics, I win as often with Virulent Strain as without. It's very perplexing, and I don't have a good explanation.
ralphmelton: (apple)

I have been an enthusiastic fan of the board game Pandemic since I first played it in 2008. I like it because it involves cooperation and careful planning, which makes it a good way to talk to people through a game. For several years, I’ve been playing a lunchtime game once a week with friends. In 2013, Z-Man Games came out with a version of Pandemic for the iPad. It doesn’t have networked multiplayer capabilities, but it works very well as a solitaire game in which one person controls all the players in the game. I’ve played the iPad version extensively, and I started recording my games as a little science project to see if I could use experiments to support our debates about which Roles were strongest. (In many years I judge science fair projects for the Pennsylvania Junior Academy of Science for the school where Lori taught; I think that investigating a game like would be a totally legitimate and interesting science fair project.)

From the first 2000 games I’ve recorded, I have discovered that the Roles in Pandemic and its expansion On the Brink are balanced better than I had expected.

(I wrote this in Pages, and then pasted it to LiveJournal - but LJ ate my tables. If you want to see the original version, ask me and I'll send you a PDF.)

Read more... )

Conclusions and Further Work

With over 500 games each of 3P5E, 4P5E, and 5P5E, I have found no evidence that any Role outperforms any other. This is a great surprise to me, because I felt certain that some Roles were excellent and some were weak. I salute the designers for balancing the Roles so well.

For future work, I’d like to measure the effects of playing with a Role that was obviously weaker. Consider a “Civilian” Role with no special abilities. This Role would obviously be inferior to any Role that did have special abilities; how many games would it take to prove statistically that it was inferior? I have considered trying to simulate this by marking one player as a Civilian and never using any special powers. But the Medic, Containment Specialist, and Quarantine Specialist have powers enforced by the game, so it would be hard to play one of those as a Civilian.

But in the immediate future, I’m more likely to investigate another path: The creators have just added the Virulent Strain Challenge to the game. I assume that I’m less likely to win with the Virulent Strain Challenge than without – but how much more difficult is it? In particular, how does the difficulty of a five-Epidemic game with Virulent Strain compare to the difficulty of a six-Epidemic game?

One final conclusion: I am still really enjoying playing Pandemic. And I have some numbers that shed a light on why. It comes down to the difference between victorious games and easy games. Even with my years of experience, over half of my games (with 5P5E) land in the zone where I win, but I feel I win only with cleverness and a bit of luck. That is my sweet spot for cooperative games, and Pandemic hits that sweet spot again and again.

ralphmelton: (apple)
Last weekend, Dave, Kevin and I tried a couple of experiments with playing Pandemic with Dave in Florida. Neither was absolutely perfect, but both were successful enough to be better than not playing.

For our first experiment, we tried video chat with Google Hangouts, with one camera pointing at our faces and one pointing at the board. We had Dave’s hand visible to the webcam pointing at the board, and we did all his moving and card drawing for him.

This worked pretty well. The down side was that since Dave had no way to change his focus, it was hard for him to read the names on cities, and sometimes hard for him to read the cards in his hand. But it was good enough to participate in strategy discussions with us.

This would be a bigger challenge with Eldritch Horror, where the fine print on the cards would be too hard to read. To make this work with Eldritch Horror, the remote user would have to take good notes.

Our second experiment was using Vassal (http://www.vassalengine.org/index.php), a Java program for a shared gameboard.

It wasn’t everything one would want from a Pandemic experience. It turns out that Vassal is really just providing a shared gameboard and not much else. For example, setting up the player deck is an eleven-step process whose only advantage over the physical game is that you can shuffle a deck with a right-click. And it was rather finicky in play; we had a couple of problems with cards getting flipped over or decks shuffled wrong until we figured out that we had to place things just so. (Voice chat of some sort would be very helpful for teaching each other how to play.)

But the positive side of it being such a basic implementation was that we had little trouble incorporating our house rules. Using our revised Special Orders was easy, for example. The one rule that might have been a bit tricky was our starting with a choice of two roles, and I have ideas about how we could do that next time.

Vassal is a modular game engine, and there have been a lot of game modules written for it. For example, there’s a module for Small World, which Andy has wanted to play with us. There’s not one for Eldritch Horror currently. There is one for Arkham Horror (and all the expansions), and one for Elder Sign, a dice game on the same theme. (But the download page says "As per FFG policy, all common item card texts are blank to ensure players own a copy. “)
We could imagine writing a module for Eldritch Horror. In practice, it would take me quite a while to scan everything and do the implementation. (The expression language used for writing conditions is pretty half-assed. Two examples of half-assery: (1) it doesn’t support grouping subexpressions with parentheses, and (2) because there’s an implicit dereference on the left-hand side of a comparison, ‘foo = bar’ is not equivalent to ‘bar = foo’.)

If we want to play Advanced Civilization again, Vassal might be a good option. It allows easy saving and restoring of games, and that might be really useful for such a long game.

Kevin said that Vassal would make a lunchtime game of Pandemic more appealing to him, because it would cut out the commuting costs. This has a definite appeal. Doing a videoconference from my office would be a bit awkward, just because of the risk that my manager might stop in - but I could overcome that. Another alternative might be to play a slower game over the course of a day, with text chat instead of live voice chat.
ralphmelton: (Default)
Very easy game today.

Five Epidemics plus the Mutation challenge. Andy played the Operations Expert, Kevin played the Containment Specialist, I was the Field Operative. (I took Field Operative to defy Andy's claim that the Field Operative was worthless.)

Our starting three-cube cities were in Ho Chi Minh City, Atlanta, and Miami. Andy went off to treat Ho Chi Minh city, and then drew an Epidemic that dropped three cubes in Chicago. This was a stroke of luck, because it meant that Kevin could treat all three hot spots in one turn. This left me to go sample cubes. I went to sample red cubes, and then I got another stroke of luck: I drew two red cards to match the one that I had in my starting hand, so by the end of my first turn I knew that I could cure the red disease on my second turn.
We managed to capitalize on that and set up Andy to eradicate the red disease on the turn after I cured it.

Another piece of luck: the second mutation cube came up in Lima, which I held in my hand. I was planning on an early cure for the purple disease, but postponed for a turn to avert a possible black outbreak - and that turn got me three black cards and an easy route to a third black cubes.

More luck: Andy twice drew four cards of a color, and it worked out that Kevin could move to a city corresponding to a card he held, and Andy could fly to that city, take the card, build a research station, and get the cure.

We won before the fourth Epidemic came out, with no outbreaks. On my last turn, I sampled a black cube, moved to a research station, cured the black disease - and then Kevin played New Assignment to let me take the Scientist role, so I could use my four remaining cards to cure the purple disease. Then Andy hopped to Kevin in Johannesburg, took his Johannesburg card, built a research station, and cured the yellow disease for a smooth victory.

Andy took this as a sign that we've mastered the Mutation challenge. I think we had such great good luck in this game that almost anything would have been easy.
ralphmelton: (Default)
Another game that seems as if it should be easier than it was.

Five Epidemics plus Mutation; Operations Expert, Dispatcher, Containment Specialist, Researcher.

We managed to get a cure for the red disease fairly early, and used Rapid Vaccine Deployment and Remote Treatment to eradicate it. This turned out to be enormously effective, because three of the cards we drew during Epidemics were in the red zone. We also managed to eradicate the black disease, blocking an Epidemic infection in the black zone. For many of our turns, we had no great worries at all about cubes on the board.

We had a plan for a yellow cure a turn or two after the red cure, but we took one of those yellow cards for a cure for the purple disease instead. But then we didn't eradicate the purple disease, and we were worrying about running out of purple cubes by the end of the game. And the deck dried up with yellow cards; half of the yellow cards were among the bottom six cards. Because of that, we didn't manage to win until the antepenultimate turn.

We did manage to win with no outbreaks whatsoever, which we haven't managed in a while.
ralphmelton: (Default)
This game looked like it would be pretty easy up until endgame, when it turned meaner than a junkyard dog.

Six normal Epidemics, Medic, Epidemiologist (buffed), Troubleshooter (buffed), Generalist.

On the Medic's second to last turn, we had no outbreaks yet, the Epidemiologist and the Troubleshooter each had a cure in hand. We had some trouble brewing with the black disease in the Middle East, but the board looked pretty good. Our chances looked good for winning the game on the Epidemiologist's second turn to come.

We came up with a cunning plan: the Medic would give the Epidemiologist a blue card, and he would discard a red card, bringing him to four red cards and three blue cards. On the Epidemiologist's turn, then, he would use New Assignment to change to the Scientist, cure the red disease with his four red cards, hop to Atlanta to meet the Troubleshooter, take the Atlanta card, and cure the blue disease. Then the Troubleshooter would cure the black disease, and we'd win.

To do this, the Medic had to give up his plans of treating the disease in Cairo, which had three cubes. We regarded this as an acceptable risk.

But he drew an Epidemic, and drew Baghdad as the newly infected city, and drew Cairo (which chained into Baghdad) among the four cards of infection. We now had three Outbreaks and a whole lot of black on the board. The Troubleshooter revealed that the Epidemiologist would draw Algiers among his infection cards, which would chain to four or five Outbreaks and exhaust us of black cubes. So instead of curing two diseases, he cured the red disease and moved to treat a black cube in Algiers. We accepted Outbreaks in New York and Essen.

The Troubleshooter then cured the black disease. We then used Rapid Vaccine Deployment to remove five black cubes and used Special Orders to push the Medic around through the black zone, vastly reducing the black threat. We were looking once more as if we could win the game with relative comfort.

The Generalist then treated cubes in Paris and Essen.

The Medic cleaned up more black and built a research station in Algiers to enable the Scientist-née-Epidemiologist to get to Atlanta to finish the blue cure. Then he drew another Epidemic, which created an Outbreak in Milan, next to Essen.
We had six Outbreaks. We were about to draw four cards out of seventeen we had shuffled onto the deck. If we drew Essen, Milan, or two of {Osaka, Sydney, New York}, we would lose.
We drew only Sydney and won the game, having gotten seven outbreaks in the last four turns.
ralphmelton: (Default)
Five Virulent Strain epidemics, Researcher, Dispatcher, Containment Specialist, Scientist. We won before the fourth Epidemic came out, with only one Outbreak on the board.

Our virulent strain was looking pesky, because the one we got first was Government Interference, which limited our mobility. But the cards worked well enough that with judicious planning from the Dispatcher, we got four diseases stomped in five consecutive turns.
ralphmelton: (Default)
We didn't play Pandemic on December 1 because none of us could attend.

On December 8, we played with five Virulent Strain epidemics with Medic, Operations Expert, Epidemiologist, and Scientist.

We kept the board under control for the whole game, but assembling cards was hard. We ended up counting cards near the end and concluding that we had six turns left to play. We then had to think for several minutes about how to get cards into the proper hands. We ended up passing two cards to the Medic and four cards to the Epidemiologist to get our cure on the last possible turn. We could not have done this without our house rule buffs for the Epidemiologist - but making it possible to win on the last turn doesn't mean that our buffs have trivialized the game.

Our house rule about choosing who takes the first turn magnifies an effect: Since the Virulent Strain is determined by which color has the most cubes at the first Epidemic, it's usually not the color with the most cards in the discard pile. The reason: the most-in-the-discard-pile color looks like an immediate threat, and so gets immediate attention, so the Virulent Strain is likely to be one of the colors that didn't get immediate attention.
ralphmelton: (Default)
I've been derelict about posting Pandemic reports.

November 3: 4 players, 6 epidemics. Failed. We couldn't keep the diseases suppressed, and it took us too long to put cures together.

November 10: 3 players (I was sick), 5 epidemics plus mutation. Failed. I don't remember the details if I knew them.

November 17: 4 players, 6 epidemics. Victory. We were looking in the face of possible defeat by the end, but we've had enough games in which we've found ourselves looking at the uvula of possible defeat that this level of peril is no longer distinctive.

November 22: 4 players (Medic, Operations Specialist, Researcher, Epidemiologist), 6 epidemics. Victory. One unusual note about this game: in the endgame, we ended up facing a choice between neutralizing a potential chain reaction, or finding the last cure three turns sooner. We ended up choosing to let the chain reaction happen in order to get the final cure.
ralphmelton: (Default)
Won Pandemic today. (Operations Expert, Containment Specialist, Scientist). I probably wouldn't post about this, but I'm trying to keep track of our success record for a while.

One unusual thing about this game: since the Operations Expert makes research stations much cheaper, we ended up playing research stations for immediate tactical needs much more than we usually do. Two examples:
• We had met in Khartoum to pass a card, two links away from a research station. But we played a government grant for a research station in Khartoum, just so the Scientist could cure and have actions left to get to a convenient spot.
• At the end of the game, the Scientist had the black cure in his hand, and needed one card to complete the red cure. The Operations Expert built a research station under him, so that he could cure, move to another research station, take the card he needed, and do the last cure.
ralphmelton: (Default)

Harrowing game of Pandemic today. (Dispatcher, Containment Specialist, Generalist, Archivist, six Epidemics)

It started off really badly. In the initial setup, we had three cubes next to each other, in Shanghai and Hong Kong. On the first turn, we treated one cube in Shanghai - but then we drew an Epidemic, drew Taipei (next to Hong Kong and Shanghai) as the city to infect with three cubes, and then drew Hong Kong in the infection phase. Net result for the first turn: three outbreaks and no red cubes left in the store. I thought that this might be a game in which we lost before every player got a turn.

We managed to claw our way back from that with significant effort - but with a lot of effort, we managed to squeak out our last cure just before things went completely to pot.

Posted via LiveJournal.app.

ralphmelton: (Default)
Yesterday's Pandemic game: with six epidemics, we managed to win the game without any outbreaks. (Medic, Operations Expert, Epidemiologist, Researcher).

We got some good luck with card distribution; the Epidemiologist needed only one card to complete one cure, the Researcher drew all five cards for a blue cure, and the Medic drew four yellow cards. We also benefited from our house rules; our change to the Epidemiologist made it easier for him to complete the last cure, and our house rule about choosing who goes first made it possible to suppress a possible chain reaction on the first turn, before we drew an Epidemic.

I also think that the Operations Expert is very strong; not only is that role extremely mobile, but it leaves mobility in its wake.

In this game, we got to a point in which we could have eradicated the red disease with one turn from the Medic, but we decided not to - and that turned out to be the right decision, because the red disease never required attention again. Usually, eradicating a disease seems terribly worthwhile if you can do it with a turn or two of work, but it seems that there are times when it's not actually worthwhile to do so.
ralphmelton: (Default)
6 Epidemics, Generalist, Researcher, Scientist.

The lesson of today's game: with Researcher and Scientist, you'll win quickly or not at all. We got our first cure on my second turn, and quickly managed to organize cures for the other three diseases, so we managed to win before the fourth Epidemic came out. (The Researcher was immensely valuable; of the seventeen cards we used for cures, he contributed eight.)

But things were looking grim: we had six outbreaks, including three outbreaks at once from a nasty triangle chain reaction, and we had lots of three-cube cities on the board. If we'd drawn another epidemic, we would have been in a very rough spot.
ralphmelton: (Default)

Harrowing game of Pandemic today. This was one of those games for which we squeaked out a victory just before inevitable catastrophe befell us.

Researcher, Dispatcher, and Generalist, 5 epidemics plus the mutation challenge.
We got an Epidemic and chain reaction of outbreaks in North America on the first turn, so that put us a step or two behind from the very beginning. We got lucky and drew our way to a yellow cure with only one yellow cube on the board, so we managed to eradicate that fairly easily-but there were purple cubes in yellow territory, so we had to go into yellow territory anyway.
During the course of the game, we got down to just a few blue cubes in reserve and clawed our way back to safety, and hit exactly zero purple cubes in reserve and clawed our way back from that.
In the endgame, our Dispatcher gathered us up on a research station, took a red card from the Researcher, and cured the red disease. I (the former Generalist, now Medic) took two cards from the Researcher, cured the black disease, and moved to the research station in Taipei to get the free treatment for the two cubes there. The Researcher went off to get a few cubes back - and drew an Epidemic that dropped three cubes in Taipei. The Dispatcher then brought back the Researcher, got a card, and cured the purple strain - but a picture of the board will show how close we were to catastrophe in East Asia.

Posted via LiveJournal.app.

ralphmelton: (Default)
We're used to barely winning Pandemic, but today's game was freakishly easy.

Three players: Generalist, Operations Specialist, Field Operative (buffed to allow sampling multiple times per turn). Five epidemics, using the Virulent Strain epidemics.

The distribution of initially-infected cities was extremely uneven; of the initial nine cities, we had about five blue cities, three yellows, one black, and no reds. And this distribution lasted - we didn't get any red cities until very late in the game.

We worked hard on tackling our blue cities, and the Field Operative allowed us to find a cure for the blue disease very quickly - and when we cured it, use of Rapid Vaccine Deployment made it look plausible to eradicate it. Eradication eluded us for a few turns, but we did manage to eradicate blue. This was a huge boon to us - it probably dropped the number of cubes we put on the board by 40%.

Then our Field Operative went to sample yellow, and with some lucky draws and research-sharing, he was able to find a cure for yellow - and with Remote Treatment, we were able to eradicate yellow as well. This meant that we had eradicated our Virulent Strain. (And luckily, the Epidemic that revives the eradicated Virulent Strain had already come up.)

At this point, we knew that winning was in the bag - particularly after we had three turns in a row in which we put no cubes on the board. We decided to try to go for complete eradication.

Unfortunately, we then had our fourth epidemic, infecting Tokyo, and drew Tokyo immediately afterward for our first outbreak. We still had a plan for achieving total eradication--but for our fifth epidemic, we drew Hong Kong and drew it immediately afterward, and it chained into Shanghai, making it impossible for us to clean up all the red cubes before we ran out of cards.

This game made us think that it is too powerful to let the Field Operative sample without limits. For our next try with that role, we might limit it to once per turn per city.
ralphmelton: (Default)
Very successful game of Pandemic today. With six epidemics, we won with only one outbreak and eradicated two diseases. We had a plan for eradicating a third disease, but we realized that conflicted with our plan for curing the fourth disease.

(Operations Expert, Generalist, Containment Specialist, Researcher. We used New Assignment to change the Operations Expert to Medic.)
ralphmelton: (Default)
Eli asked me for our house rules for Pandemic, and I'm moved to chronicle them here as well.

Our Pandemic house rules:
For the basic Pandemic game:

• Play the Operations Expert as specified in the On the Brink expansion: as well as building a research station without spending a card, they also have the power to fly from a research center to any location by spending any city card and one action.

• Choose who goes first communally, after choosing roles and looking at your initial cards and the initial disease distribution.

For the On the Brink expansion:

• Deal each player two roles, of which they choose one in consultation with others.

• The Troubleshooter may examine the top cards of the Infection deck at the beginning of every player's turn, not just his own.

• The Field Operative may sample multiple times per turn.

The Epidemiologist is still giving us trouble. As written, it seems too weak, but letting him take cards multiple times per turn was too powerful. My current idea, which we have not tested:
• The Epidemiologist may receive cards that do not match the current city on any player's turn, but only once on each player's turn.
ralphmelton: (Default)
Today's game: Troubleshooter (buffed), Epidemiologist (buffed), Dispatcher, Containment Specialist, six Epidemics. Won after a harrowing game in which we were not just flirting with disaster but had progressed to heavy petting. I don't think we could have won without the house rules buffing Troubleshooter and Epidemiologist.

I particularly like our buffs for Troubleshooter, because when we change our behavior to handle an imminent crisis, it adds tension and makes us feel the danger more keenly. In this game, for example, the Troubleshooter's ability let us turn a three-outbreak chain reaction that would have ended the game into a one-outbreak milder disaster. This made it possible for us to win--but it also prolonged the game and kept us on the edge of our seats for longer. And that's good for the game.
ralphmelton: (Default)

Barely won Pandemic today. Found our last two cures on the antepenultimate and penultimate turns, had seven outbreaks when we won, came close to running out of yellow and black cubes. Roles: troubleshooter (buffed by house rules), researcher, containment specialist, archivist.

Posted via LiveJournal.app.

ralphmelton: (Default)
Last Wednesday, we played one of our most nailbiting games of Pandemic yet. (Operations Expert, Dispatcher, Medic, Epidemiologist, with five Virulent Strain epidemics.)

We drew the Rate Effect card early, which means that whenever you draw a card of the Virulent Strain color during the Infection Phase, you draw another card. This gave us a lot of trouble throughout the game, because we had plenty of Virulent-Strain cards in the deck.

We had seven outbreaks by the end; another outbreak would have meant doom. We also ended up with zero black cubes in reserve at one point; drawing a single black card in the infection phase would have lost the game for us. But we won by the skin of our teeth.

Here's a picture of the board after we won. Experienced Pandemic players will recognize this as a board in great peril, with nine different cities that had three cubes, three of which could outbreak before the next epidemic.

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