Just a short post, but I saw some folks quite excited as Jake Fox hit his 9th home run of Spring Training. I do not mean to be pessimistic, but just to temper expectations. Since 2007, there have been 26 instances of a player hitting at least six home runs in at least 50 at bats. Actually, there have been 28. I did not include two players who did not appear in any regular season games.
I compared HR per At Bat from Spring Training to Regular Season. Players had a 56 +/- 18 % decrease in home run rate. Jake Fox is averaging 7.22 at bats per home run. A 56% decrease would mean a home run every 16.4 at bats.
That translates to 30 home runs every 500 at bats.
The 95th percentile would put him between 18 and 42 home runs per 500 at bats. Anything above or below would be significantly different.