In case you missed it here are two references to a battery of tests performed at St. Louis University on Albert Pujols.
What was interesting was that these were similar tests performed on Babe Ruth in 1921 by graduate students at Columbia University. The September issue of GC magazine include more detail but both not surprisingly scored very well. This kind of analysis may bear some light on the question of how players have improved over time. The unfortunate thing is that the tests Ruth took weren't as well documented or controlled and so comparisons are probably pretty difficult.
One of the more interesting tests was this one:
Asked to place a mark through a specific letter each time it appeared on a page of randomly positioned letters, Pujols used a search strategy that White had never witnessed in 18 years of administering the test.
"What was remarkable about Mr. Pujols' performance was not his speed but his unique visual search strategy," White said. "Most people search for targets on a page from left to right, much as they would when reading. In observing Mr. Pujols' performance, I initially thought he was searching randomly. As I watched, however, I realized that he was searching as if the page were divided into sectors. After locating a single target within a sector, he moved to another sector. Only after locating a single target within each sector, did he return to previously searched sectors and continue his scan for additional targets."
There is also some nice video of Pujols performing a swing test where he came out at 86.99 mph using a 31.5 ounce bat. Ruth, on the other hand, swung a 54-ounce bat an estimated 75mph.