Take the most dominant pitcher from the entire history of baseball, whoever you consider that to be, at the height of his prime/ability/dominance, and pitch him against the greatest hitter ever, again whoever you consider that to be, also at the height of his abilities.
Given 100 at bats, who comes out ahead? 1000 ABs? X number of ABs?
Too late to edit: A “win” for the pitcher would be making an out, a “win” for the batter would be a hit or walk. Assume there is an at least average defensive team on the field (they’ll easily make all of the plays that a veteran MLB fielder should make).
Depends on the conditions of contest, and what constitutes a win for the hitter. If the hitter takes 100 or 1000 consecutive at-bats against the same pitcher (allowing a cheat code to give all involved unlimited stamina), and the hitter wins if he bats .400 or better, I think the outcome favors the hitter. He’ll see everything the pitcher’s got in the first few at-bats, and be able to get his timing down. If he has to bat .501 or better, then the pitcher probably wins…but it would be fun to watch.
Walks don’t count as at-bats and aren’t figured as part of his batting average, so you’d have to invent a new scoring system to give some sort of credit for a walk…
The OP doesn’t specifically state the at-bats are one after another, so we already have a good idea what the answer will be from the record books.
If the at-bats are one after another, the batter will get better from seeing the same pitches over and over again. I don’t know if that will carry him over .500 even with the walks, but it complicates things a little. 100 at-bats may not make the difference. 1000 at-bats could make the most dominant hitter of all time a lot better at hitting that one pitcher.
In all of this you can’t account for the possibility that either the batter or pitcher is a lot smarter than the other and this will be an unexpected wipeout instead of an exciting contest.
For hitter I’ll go Rod Carew. I watched games where he’d stand in the box and foul off pitch after pitch for an eternity and the jump all over the one he really liked.