My preferred key setup from playing this on MAME


With this setup:

Batting
A = Full Swing
D = Bunt (just taps the ball, a defensive block for a fast pitcher)
S+UP= Steal 2nd (If you have a player on 1st)
S+LEFT=Steal 3rd (if you have a player on 2nd)
S+DOWN=Steal Home (bad move, unless you hit it or bunt it to give a running start)
AI pitcher is sometimes wise to steals and will throw the ball to bases, beware
Supposedly bashing A (red button in arcade) makes the players run faster to bases, but I never saw any difference tbh.

Pitching
A+DOWN = FAST BALL
A+LEFT/RIGHT= CURVE BALL
A+UP = SLOW BALL (is a ball unless AI swings at it)
Note: You can only do two slow or fast balls in a row

S+LEFT/RIGHT/UP= Throw Ball to Base (If AI tries to Steal)

Fielding
A=Jumping/Diving Catch (If ball is incoming to your fielder)
A+UP/DOWN/LEFT/RIGHT=Throw to base/player (If you are a long way away, it will make a two part throw to base)
S+UP/DOWN/LEFT/RIGHT=Run to Base (Best used if you are close to the base when you pick up a grubber ball)

You can also use the S+Arrow key to move between bases to run players out, or use the A key to throw it to the base keeper ahead, this can result in some benny hill moments as you throw ball ahead of the AI, and then it tries to run back to the previous base, and so on :)

Pinch Hitter
Just a word of warning, If you use a pinch hitter when your pitcher is up to bat, you must bring on a new pitcher immediately afterwards!

Pitcher Fatigue
Your pitcher can only throw a finite amount of balls before getting fatigued (on the portrait, instead of chewing gum, he'll be gasping for breath) When this happens, you can't throw a slow or fast ball, only a standard pitch (you can still throw a curve ball though)

Hit by the Pitch!
Try not to hit the AI with the pitch, 1/2 the time they'll rush the mound and smack your pitcher, this fatigues him instantly! You can use this to your advantage, the AI will sometime throw curve balls close to your Batter, just move him over using the arrow keys and it'll hit him, then he'll either take a base or rush the mound. Its much easier to hit the AI pitches if they can't throw a Fast or Slow Ball! :)