I saw this brought up on Twitter and thought it was an interesting question:
Say you took an average guy who is reasonably physically fit who has never played baseball before. How many at bats against a major league team would it take for him to get a base hit?
Would it be relatively easy? Or take a long time?
Bring a Kindle and a sleeping bag.
It depends on his inherent athleticism. If he actually had latent MLB potential, he might eventually get around on one.
Someone like me?. Not a chance in hell. Ever.
My opinion is that it would take a long, long, long time.
I think you need to split this into two questions. Because you’re specifying that the guy has never played baseball before, but as time goes on he’ll have more experience and will get better. So the question is whether you mean any one guy playing until he gets a hit, or do you mean the percentage of such guys who would get a hit in their first at bat. The answer would be different for the two questions.
In any event, I highly doubt if “an average guy who is reasonably physically fit” would have a BA higher than .010 against major league pitching and defense. How many ABs it took for his first hit would be a crapshoot, though.
I think an average of 0.010 is excessively high. I played baseball as a kid and was OK. I tried batting against a quality fast-pitch softball player as a young adult, and I whiffed badly on 10 straight pitches. This was softball against an amateur pitcher. No chance in hell I’d average a base hit every 100 pitches against a major league pitcher trying to strike me out.
I think just making contact in the first 100 pitches would be a huge stroke of luck, and it would take thousands or tens of thousands to get an actual base hit.
“Against a major league team” is an interesting criteria. Mainly because the only part of the team you have to care about is the pitchers. Sure the other players need to be there to see if it’s a fly out, but it’s actually hitting the ball that will be the hard part.
Is this a “he is miraculously added to a MLB team roster and plays in the lineup as DH” or is this “Homie has to sit in the batter’s box until he gets his hit?” The former makes it easier for Average Joe, as he might get lucky with a tired pitcher in the ninth. The latter means Average Joe is screwed, as the pitchers rotate out and Joe gets incredibly tired after the 20th swing. Plus he still has to make it to base unless he homers.
Homering might actually be our guy’s best bet, since his foot speed to first is probably not going to be enough against major league ball players making a play. Maybe if it was a ‘real’ game and AJ could anti-sacrifice bunt to get himself onto first at the casualty of getting the guy on third out?
How about no fielders but a hit ball must travel (arbitrary) 150 feet in the air or on the ground to count as a “hit”.
How far does the average bunt travel uninterrupted?
It occurs to me that this might be gaming the question a bit too much.
Is the pitcher actually trying to get the guy out? Or just throwing fastball after fastball down the middle? I think if it’s the latter, the guy is probably going to get one in the first 100 pitches just by timing the pitch, swinging way early and getting lucky.
If the pitcher is using his full arsenal (mixing in off-speed pitches, not making every pitch a strike, etc.), then it could take days.
I picked .010 off the top of my head as an upper bound.
But I’m thinking if you struck out 19 of every 20 AB, and had a BABIP of .200 (vs the standard .300) then he could hit .010. And striking out 19 of every 20 AB means whiffing on more than 19 of 20 pitches, since you get 3 shots each time (though you might take some looking).
Does the batter have to swing at every pitch? He could wait until the pitcher has thrown 250 balls and only then start swinging. The batter would get much better results then 
It’s unlikely he’ll make contact for a very long time but with no fielders I suppose a lucky hit will send one past the baselines. If this guy has never swung a bat, and doesn’t get any practices between pitches it could take hundreds of pitches before he gets that lucky contact. It will probably happen when pitchers get over confident that the guy can’t hit anything and lob a meatball over the plate.
No bunting. While bunting isn’t as easy as it might seem to be, it’s still not timing and swinging at a pitch.
“I’ve got 250 chances to envision exactly how foolish I’m going to look once I actually start swinging at these! Awesome!”
He’s going to look extremely foolish no matter when he starts batting. Might as well wait until the pitcher’s arm has turned to rubber and the fastballs are ‘only’ coming in at 80mph.
FWIW the premise of the question assumed the team in the field is playing to win and the average joe was part of a rotation.
Facing a 100 mph fastball, a batter has .3 seconds to determine where the ball will be when it reaches the plate.
For the OP’s batter, it may take a more than a lifetime before he gets a hit.
So he’s playing against serious competition from Major Leaguers, and he’s only seeing three or four at-bats per game? Considering there have been actual major leaguers who have struggled to get a hit after numerous opportunities, I don’t see your hypothetical person managing at all during a season.
The Strike zone isn’t that big. Eventually the Ball and bat will end up at close enough to the same place at the same time to get a bloop over the infield. Assuming he can get to first in less than 7 seconds or so, which a reasonably fit dude could do.
Another interesting data point, or at least an approach to study this statistically:
Our hypothetical noob hitter is stipulated to have never taken a swing at a professionally-pitched baseball in his life. Just bring his native reflexes and hand/eye coordination to the batter’s box.
How many professional baseball players never see a Major-League pitch? How many guys languish their entire career in the Minors? If they could hit reliably, they’d come up (possibly). These are folks with the natural talents to get drafted into the system, and the experience in the upper echelons of the pre-professional system (e.g., college baseball) and still can’t be counted on to be able to put a bat to a fastball pitched by even a journeyman MLB pitcher.
Fewer than 10% of minor league players get the big call. Estimates are as low as less than 1%.
What chance does our noob have, other than a lucky swing that makes contact in a hard-to-field way? Other than that, expect hundreds of pitches.