For some mysterious reason, every team has those one or two guys that are their Achilles heal. Whether it is match-ups, familiarity, or just luck, often enough these players are average to below average players that just have their way against certain teams.
Take Scott Hairston for instance as he was known to hit well in AT&T Park and destroy the Giants. In 212 career at-bats against San Francisco, Hairston hit .259 with an outrageous 14 home runs and 32 RBIs. If he kept this pace throughout a complete 162 game season, Hairston would tally about 40 home runs with 96 RBIs.