Yes iScore can handle. but not "automatically" .. It will take focus on the part of the scorer, and liberal use of batter substitutions.
iScore can handle because iscore a) lets you substitute freely, b) lets you separate offensive and defensive subs and c) lets you bat as few or as many players as you need.
iScore follows a 'score what you see' approach - so when "batter 1A" comes up to bat his second time, you simply tap batter icon and sub in "batter 1B". then sub back "batter 1A" when the spot comes up to bat again. this will take focus on the part of the scorer, as you will have to do it for each batter. ( or better yet, establish a personal workflow to mass swap batters, every time the line up turns over (approx 3-5 times a game), so you are not having to do with every at bat. )
When you set up the starting line up and then manage the subs correctly, The stats and scorcard will be perfect. It is also noteworthy, that because iscore tracks action by batting position (i.e. batter 1 slot, batter 2 slot, etc) (not name Name A, Name B, etc ), if you miss a sub, you can go back later and correct - either during or post game using play-by-play Editor.
I would set up your starting lineup as below, positioning the A/B pairs next to each other.
(positioning A & B next to each other in starting line up will make substitutions much easier to find and faster during game.)
- Batter 1-A batting = yes
Batter 1- b batting =no
Batter 2 -A batting =yes
Batter 2-b batting =no
Batter 3-A batting = yes
Batter 3-b batting =no
..etc etc ...
Batter n -A Batting =yes
Batter n - B Batting = no
THEN, in game, when the top of the order, lead off batter slot 1, comes up the second time, I would tap the Batter icon, and not only swap Batter 1A with Batter 1B, but go ahead and swap all As to Bs for the whole Line up from 1 to N. Then repeat "mass A|B swap" each time "lead off batter" comes to bat. thus you will only having to worry about this a few times a game vs every batter.
Also note, in game options the setting for "simultaneous subs" should be set to NO (the default value), so you can sub batting and fielding changes independently.
All in all, though not designed for A|B play, Iscore can handle pretty darn effectively, with just a little extra work on scorer part.
Enjoy,
/OhioTex