Broseidon
M.F.C.E.O.
To be fair...hitting a 90 MPH fastball is the easy part. You can gear up for a fastball. Its having to account for everything else (and having the bat speed to adjust), that's the hard part.
If you KNOW you are going to see NOTHING but a fastball...then you can make adjustments for it / start your swing earlier / etc. and probably get a few hits. I believe I could do it...then again, I'm 27 and havent lost much off my bat speed since my playing days.
The HARD part... is if everything is mixed in. Changeups, Curveballs, Sliders, etc. The changing of speeds and location... is what is killer. Good luck trying to pick up the seams to figure out what type of pitch it is.
90 is a slow fastball in the show, and maybe you could sit on that, but Im thinking if the pitcher buzzes one up and in ... You're probably gonna be less likely to dig in and sit fastball. Add to that the pressure of a huge crowd and devastating breaking balls...and, yeah, I'll take the under