Is the Smith-Morra Gambit a good idea for regular play?

Is there data to support this?

I don't need data - personal experience can suffice. I've played a lot of blitz games in this line against titled players already and adjusted my prep accordingly several times, helping me understand the lines better and improve my course. I can name a specific example: GM Miroslav Miljkovic made a specific sharp move after a forced sequence on move 14, which I didn't know how to react to in blitz. I got outplayed as I didn't realize the difference between my prepared move. I analyzed it, learned the nuance, and later crushed a 2450 in blitz as I remembered the improvement, understood it, won material, and cleanly converted.

There is also conclusive evidence that analyzing my blitz games helps me improve. My blitz improved more than 250 points this year and I've noticed that playing blitz games and looking for opening improvements helps me remember my lines and make previously patterns (after applied in blitz) stick.

More likely to be found in slow games?

He's right that blitz contains plenty of moves a player would have as candidates OTB. This is a way you can find practical tries against lines that an engine wont show you, and you may not be able to come up with on your own.

More rarely, even lines that are outright better than an unprimed engine... IIRC it takes the engine a long time to like Esserman's Nd5 (ok, so maybe he didn't play it first, but he popularized it).

Is that evidence that important moves are not being missed?

Probably, but you can play many blitz games in the time it takes to play one slow game. Perhaps only one out 6 blitz games (arbitrary number but I've seen gold in many blitz games and learned a lot from them) will contain gold, but that still takes less time than playing an OTB slow game (which will probably be slower than g18), even assuming that there will be gold every game.

45 engine games, dozens of hours of analysis, 3 FM beta-testers, 6 NM beta-testers, Esserman's book, dozens of blitz games against titled players.

"... IMs and GMs can find tricky moves that aren't the engine's top suggestions (even in blitz). …" - LogoCzar

But are they more likely to find them in slow games?

It's possible that there are still some important moves that I failed to cover. At this point, I think I covered what is theoretically critical and proven an advantage. At this point, I think additional games can reveal practical tries for White that are insufficiently covered. Therefore, I's like to play many more Morra games against titled players. FM @anishizback refuses to play me in more Morra games though, as he was convinced by our last match that the Morra is refuted. I'll have to find other opponents.

Answered this already. Tricky moves can still be found in blitz. The likelihood is lower, but it's still more efficient than playing slow games. And I don't exactly have a GM slow-game practice partner right now, though I get paired up with GMs somewhat regularly in blitz (my chess.com blitz peak is 2517).

"... IMs and GMs can find tricky moves that aren't the engine's top suggestions (even in blitz). …" - LogoCzar

But are they more likely to find them in slow games?

Don't remember you giving a reason to believe in this greater efficiency.

If there are 3-5 plausible moves in a position, there might be one best move. In the slow game, an IM or GM is more likely to play the best move. The IM/GM is likely to pick one of the 3-5 moves in the blitz game. Assuming 5 moves, chosen randomly (this is a stretch), it's supposedly 5 times less likely for the move to be found in a blitz game. I'm exaggerating for your sake - GMs can be very accurate even in blitz. If it's 5 times more likely in slow chess, 5 3/0 games would be equal to 1 15/0 game from this perspective. g15 isn't even slow chess, it's rapid. It's simply more efficient to play blitz here, provided that I analyze the games.

Is that a reason to believe that slow games would not be better?

Even Botvinnik (the guy who said blitz was bad and never play it) played some blitz games as a tune up for his WCC match (with curtains drawn and strict orders not to tell anyone).

We didn't find about about it until the guy (forget his name) was practically on his deathbed, many decades after the fact.

I have no idea why you keep going on about this. I don't need to convince you that I don't need slow games for this. Many of the blitz games that I've already revealed a lot.

Is there reason to believe conclusions from an unverified assumption?

Is that a reason to believe that slow games would not be better for revealing stuff?

Like many of your recent challenges, that's not germane. He never made that claim, and he's already explained this is part of a larger whole.

If I didn't know you better I'd say you're trolling.

"... it's still more efficient than playing slow games. …" - LogoCzar