Ideally what you want is for a player to choke up, protect the plate, and make more contact WITH 2 strikes. Not always. Nowadays every player takes the same approach every pitch (looking at you Rickie Weeks as exhibit A) What they should do is take their normal huge swings until they get to 2 strikes and then protect, unless they are are able to put up decent numbers with 2 strikes using their normal approach. These are usually all-star type players however. In 2002, Jose Hernandez's best year when he struck out 188 times, his 2 strike line was .176/.219/.260/.479. 7 2B, 1 3B, 6 HR. That OPS is 24% below the league average, including pitchers hitting numbers. So it looks like JH should have choked up with 2 strikes and he would have had a better season, but only with 2 strikes so he would not have had to sacrifice the other power stats he got. Take Mark Reynolds in 2009, 44 HR with 223 K. He was able to OPS just 6 points below the league average with 2 strikes while adding 14 2 strike HRs. So he would be an example where you probably would not need to adjust the approach with 2 strikes (except for key situations like R3 < 2 O but that is another topic) since he doesnt really suffer as much taking a huge swing with 2 strikes.