So I've been working on a computer version of San Juan, because I wanted to try my hand at A.I. I've got a semi-finished product (the A.I. is mostly good but the interface needs some work), so I did what any good geek would do...
I had my A.I. play itself for 1000 3-player games and logged the results for further analysis.
Here are some insights I was able to make based on the results.
1. Player 2 has a considerable advantage.
Here are the actual numbers of games won per player:
Player2 354 Player1 331 Player3 315
Player 2 has the advantage because in the first round, there are only two roles that are of any help. The builder and the prospector. Player 3 ends up taking the mayor, or possibly the producer if they happened to build a production building. Meanwhile Player 1 has to wait 5 more turns before being able to select a second role. Since the Builder and prospector offer nearly identical advantage in the first round, Player 2 essentially gets the best role 2 rounds in a row and a nice head start.
2. The carpenter is the best choice for a first build.
Here are the winning percentages based on first building built: