Is it possible to throw more than 255 pitches in a game?  I know 255 is common limit in programming, but I was just curious if that is the case here.  Look at the game logs for the following guys:

http://www.whatifsports.com/HBD/Pages/Popups/PlayerProfile.aspx?pid=3107504

http://www.whatifsports.com/HBD/Pages/Popups/PlayerProfile.aspx?pid=3107499

http://www.whatifsports.com/HBD/Pages/Popups/PlayerProfile.aspx?pid=3283741

In all honesty, it's the most unrealistic thing to expect a pitcher to throw more than 255 pitches in a game - but if there is a limit at 255 having a limit technically is "unrealistic".  I'm not interested in changing anything, this is more my own curiosity than anything.

On a similar vein, are there other "programming" limits that exist in the game that we have yet to find?

255 is the max.  Same with the number that show ML service days.  It's probably an 8 bit figure, so in binary when the value can be 0 or 1, you get 2^8 = 256.