ST is the time pitchers use to fine tune their skills including working on new pitches; batters work on timing - but you also see AAA, AA even A pitchers facing the elite hitters. I learned many years ago that you can't expect someone hot during ST to carry over to season numbers - even teams that go through ST without losing can start the season in the tank.
Thoughts about how the game have sadly changed with implementation of cybermetrics/sabermetrics -heck just using computers - it takes the human quality out of the game- going with a hot bat or just a hunch this guy can hit a certain pitcher; Call me old fashioned but it was more fun watching baseball in the 50s & 60s. Even in the same 70s or struggling 80s . Most of your computer geek experts never played baseball & just feed numbers into their 'toys' & 'swear' by the results a machine spits out. Managers are told they don't have to follow those results to the letter BUT they better be rirght or else. In other words to go against cybermetricians puts their job on the line.- I strayed from the question but just wanted to put some lingering thoughts in print.