I’ve had fails spawning I believe up to 15 gems spawned on board with 11 without getting a match 4, possibly even 16/12, but very rarely, and I don’t recall any 17/13. I’ve failed plenty of 10 to 12 spawns on boards of high 10s, and even low 20s (Elemaugrim with burning enemies, Aurora).
This topic is going to be very one sided if you only have people list those, though. I’ve also had match 4s spawning 7 gems on a board with 5 or less (not counting when they were broken to be autolinking). The RNG cuts both ways, and you can get gigantic cascades off the tiniest of board mod, plus a single random extra turn can lead you into taken a dozen manual matches that conveniently fell into place (yes, for the player too, not just the AI). Also keep in mind that position, not just count, matters, as gems at the edge of the board have fewer locations where gems can spawn that they would be a part of a resulting match 4 or 5. With that in mind, start making decisions you know are extremely terrible with random spawners and you’ll eventually see all ranges of successes and failures, regardless of what you have considered beforehand. Because they are random.(*)
*(influence to make them “miss” aside, which has been repeatedly stated to only occur after five spawner casts in the same turn and resets every turn)
@Lyya The missed matches are the “L” shaped and cross shaped match 5s in the first example