The decks with good dragapult matchups
First I'll be setting a hard cutoff at 100 matches minimum otherwise the data is too noisy to really draw a good conclusion.
Using limitless labs data we can see what decks are good vs dragapult. There are a non-zero but small number of decks that fit this Decks will be discussed with +/-/= notation from chess, and a "match points adjusted win rate"
I will consider any deck with a >50% MP adjusted win rate to be "good" into dragapult
#Crustle +101 -39 =15 (68.39%)
Crustle is easily the best performing deck against dragapult by a country mile. Even in LA where Crustle was extremely unpopular we see that significantly less than half of all dragapult players teched for Crustle. Even if you do tech for crustle crustle is resilient enough to fight some good fraction of techs, the main exception is that dudunsparce EX is legitimately very good in the matchup and the Dudunsparce build really does significantly over-perform
However legitimately while it didn't have results in LA it also saw tiny play in LA and sample size is the most important thing to remember about statistics. Study Simpson's paradox to understand why.
In general I highly recommend this deck the underlying numbers are too good. Even if you assume Dudunsparce will pick up play rate the vast majority of pult players are still disrespecting Crustle to a large degree
Variant breakdown
Pure pult 85.48% Blaziken 79.17% Dusknoir 36.78% Dudunsparce 28.17%
Basically you feast on the pure pults, but the Noir/Dudunsparce builds give you trouble due to actually being good at fighting crustle. But you feast on pure/blaziken super hard and that build is still far and away the most popular. (though I think blaziken is on the way out) Note that the sample size for these is too small to draw a real conclusion, but they do pass a gut check.
#Cynthia's GarChomp +221 -150 =47 (56.62%)
This deck actually did perform pretty well against dragapult, however unlike Crustle this deck was significantly less well rounded Doing extremely poorly into Rocket's mewtwo, Alakazam, Ogerpon Meganium and Raging Bolt
So in spite of this deck having a strong time into Dragapult the deck's overall performance was quite poor. Unlike Crustle Who actually did quite well. I would therefor not recommend this deck even though it did beat Dragapult
#Raging Bolt +224 -183 =68 (51.93%)
So now we get into soft counters. of which there are 3. Raging bolt is extremely well rounded, and in part it's a sign of reverse power creep that raging bolt without sada's is so good and part of it is that Raging bolt slop box is a legitimately good strat with a lot of flexibility.
One really key factor in raging bolt's success against dragapult is that Raging bolt has >200 HP and can one shot dragapult.
this is an extremely critical factor that is hard to understate. Lilie's clefairy has only 190 HP and gets counter one shot by dragapult, while raging bolt can tank a hit and get the damage healed off by Chien pao+area zero underdepths. '
In general if you want a well rounded deck that is actually good in general that also happens to be decent into dragapult then this is the best option. (well other than Crustle)
Variants breakdown
Pure 53.76% Dusknoir 56.45% Blaziken 52.72% Dudunsparce 36.82%
Again you struggle to the tenacious tail attack, but other than that you have a strong set into all builds of pult, being more well rounded into pult as a whole.
#marnies grimmsnarl +55 -47 =15 (51.28%)
This is where I get into sample size issues. Trinomial confidence intervals don't exist, but if we assume 13% tie rate as a constant, and just leave that alone, then our 90% confidence interval contains 45% to 62% as the win rates (excluding ties) against dragapult. Using Beyesian inference methods we can predict that the mean regression will be more likely to be toward 45% than 62% (as the deck's overall performance was poor)
As such I can't recommend this deck and I wouldn't be surprised if its success against Dragapult was a mirage
#Mega lopunny +68 -61 =28 (49.26%)
So our last deck in the list. Technically falls just outside the range but Hale did well and I feel obligated to talk about this deck given that it had a great overall showing in spite of only being "ok" into dragapult. The sample size is also an issue for sure, but again this is mostly about it's peripheral performance even if the dragapult numbers are nothing special.
I still like the deck and would definitely suggest trying Hale's build, the Lopunny wally's compassion spam is strong, and mega lopunny is even good against Crustle thanks to spiky hopper putting in work.
Overall
I suggest 3 decks to beat dragapult
Crustle: the big one weak into some variants but more resilient than you'd expect, you also just munch the most popular builds of pult
Raging bolt: if you don't want to play Crustle play bolt you'll basically be playing good big basics and actually have a decent time. The deck is also decently well rounded and has quite a few cute tricks that are underappreciated.
Mega Lopunny. Tank deck with cool tricks and can hang with the big boy. Also has a much better time into tricky matchups than you'd expect thanks to well rounded strategy. Even if it does fold to fighting decks.