Henka in Sumo is a classic legal but unsportsmanlike move, particularly for higher ranked wrestlers.
Baseball has a lot of these, maybe more than any other American sport. What the old timers used to call “chin music”, once a normal part of the game, absolutely incenses modern batters even if they are crowding the plate and inviting the pitcher to jam him inside. God forbid you should push a tweak a batter with an inside fastball. LOL
So throw inside. Just don’t go headhunting or deliberately try to hit the batter. The pitcher already has a huge advantage, the batter should be allowed all the plate he wants.
Or allow the batter to charge the mound with bat in hand.
I understand, but I’ve seen batters become militant because of a fastball thrown 4 inches inside at their waist.
And I’ve seen pitchers throw at batters for having the temerity to have gotten a hit.
Maybe they all need to grow up. Not that all this is anything new.
Well, the OP is asking for legal actions that are considered “jerk moves”. Pitching a guy inside and pushing him off the plate is legal, but intentionally hitting batters is not legal and can get one ejected. The former is strategy and the latter revenge.
When you’re playing a game of Strategema against a better opponent, perhaps a level 3 grandmaster even, and instead of trying to win you deliberately play to a stalemate. Bad form.
Hitting a batter on purpose is not legal. It results in a penalty being applied to the team in question, including ejection and suspension. The ump doesn’t have to warn you, either.
Is making a noise when another golfer is concentrating against the rules?
Not just skillful, but monopolizing the available housing is an intended tactic.
Another Monopoly “example”: many people will think you’re a jerk for insisting on playing strictly by the rules.
I’d add for tennis the “moon ball”, where the player sends the ball on a very high lob, with the intent that even after the ball bounces, it’ll still be too high for the opposing player to make contact.
I see underhand serves and moon balls all the time in juniors tennis. Teenagers are jerks. 
I’ve played tennis for over 40 years and I don’t think most people would regard the moon ball as anything worse than a drop shot.
The underhand serve on the other hand…
Sometimes a wonky serve is a jerk move; sometimes it’s a strategy.
Wow. Just watched some videos about it. Never heard of or saw it before. Interesting.
Whether or not the underhand serve is a jerk move, in my experience every player I’ve ever met in real life who employs it is a jerk in other ways (bad line calls, constantly disputes opponent’s calls, creates disturbances, fussed about facilities, turns up 14.5 minutes late for a match, etc)
Interesting. For the kids I watch, moon balls are almost “fighting words”. Basic tennis has them hitting the ball when it’s near the top of its arch, so until they learn how to hit on the rise, moon balls are literally untouchable for them.
Underhand serves are annoying, but a standard way to punish the receiver for being too deep behind the baseline. My son’s junior tennis team practices it. Little different than a slice serve or kick serve. Players need to be able to mix things up, especially when they’re down.
I’d add that drop shots are considered jerkish if that’s all you’re doing.
On preview: @Gyrate, yep!
Yeah, running up the score late in the game when you’re already far ahead is considered especially jerkish behavior in College Football. Case in point the infamous 1968 Michigan - Ohio State game, when Ohio State went for two points late in the 4th quarter, after scoring a touchdown to put the score at 50-14.
The ‘official’ reason they gave was because their center was hurt so their field goal kicker was subbing at center, but reportedly OS coach Woody Hayes said when asked why he went for 2, “because I couldn’t go for 3”.
A few years ago coaches in the NFL figured out you could run out the clock near the end of the game by taking a delay of game penalty followed by a false start. They ended up closing the loophole that summer.
In auto racing, especially NASCAR, dumping the leader to win a race. Back at the short track where I drove race cars, dumping a car for any reason meant a black flag and you were our of the race. The only time NASCAR got this right was at Sonoma in 1991, Ricky Rudd was black flagged for dumping Davey Allison. Allison was given the win. The worst example of this was an Xfinity race at Martinsville last year. Ty Gibbs dumped his teammate Brandon Brown to win the race. It also knocked Brown out of the series playoffs. Gibbs father called out his son, calling his a jerk for what he did.
Counting cards in Blackjack. It’s not so much that it’s a “jerk move” against the Casino, who deserve whatever they get. It’s a jerk move against other players because the casino has to make blackjack a less enjoyable game in order to counter the counters.
Counting is legal by the letter of the rules of the game, but you’re not some card playing savant flexing your amazing skills, you’re just counting based on fairly straightforward rules.