This would imply that “combo breaker” is no longer a thing, which is a widely known and admitted gameplay mechanic which is intended to only negatively affect AI skyfalls in certain conditions. When skyfalls and initial board state were talked about waayyyy back in 2016 (before the unity port even, so different codebase), it was heavily implied that the gem falls and initial boards are the same for everyone but conditionally manipulated in a different part of the code:
The storm implementation explanation makes sense, though, and brings to light why doomstorm currently feels so bad to use. The thing that kills it is having so few skulls in total that you are unlikely to get a match from a board clear compared to any other storm. If doomstorm can’t raise normal skull chances without raising doomskull chances because of the implementation of randomly replacing gem that would fall with this specific gem rather than actually changing how the gems are weighted then it would seem that they “had to” have a barely increased overall skull chance for doomstorm to not be ridiculous.
But this infographic only references the 3.5 doomstorm change. There were two changes, one in 3.5, and one in 4.0. The first one was still sort of workable. The second one killed it. Before the first change, a great majority of skulls that dropped were doomskulls, and skulls also dropped almost as much with a bonestorm out, so no idea what the coded implementation of it was at that time since it seemed like much fewer than 10.9% of total drops were “normal skulls”, since that would have meant close to 40% of total skulls were normal skulls, and that doesn’t align with the experience I had. After the first change, it seemed like still increased skulls but much fewer of them were doomskulls percentage wise.
The infographic seems up to date with reference to Electrostorm, so its probably referring to the current version of Doomstorm. Each of the nerfs was a noticeable change at the time and unlikely to just be a patch miscommunication.
3.5:
4.0:
(The quotes should contain links, if not, these are the original initial patch notes for those versions.)
Even if Doomstorm must spawn a barely increased number of Doomskulls to keep chain-reactions in check, having the number of matchable-gems being so barely increased. Nearly every match nowadays is played with the majority of it having a storm in play… this is the norm, the opposite is the exception. Triggering a doomstorm currently is closer to no storm than it is to having any other storm in play as a practical application on any team. Board clear without extra turn and skull countermeasures is unreasonbly risky to the person initiating, board clear with keep the turn even results in generally messy boards you can’t follow up on due to both lack of mana and lack of conversion openings (take Leprechaun into a fight versus Shade of Kurandara or any hero class with the doomstorm start without overwriting with your own storm). Where initial doomstorm either one of these was often a straight up first cast win condition, it now generally results in either a troop death or stall on the player who is initiating/attempting to capitalize off it. In its current state, I’d count triggering a doomstorm as generally a downside, even if you maintain advantage with an otherwise appropriate team, unlike every other storm, when the triggers for it (ie., it being on a legendary trait as an “on kill” storm trigger with every other color “on kill” version being a minor trait) clearly show it is meant to be an upside.
A sensible change here, if they believe too many doomskulls were falling to “chain react” and causing a insta game-end condition after triggered with a single board clear if they just increase doomskulls but while still making doomstorm desirable to have in your kit, would be to implement doomstorm as a dual color doomskull-skull storm. A ~7% gem replace check on skulls then doomskulls would bring it in line with other single color storms, which it should be treated as because skulls match with doomskulls unlike the gems from dual color storm and this would bring the total skull balance to just below what it would be on a normal bonestorm with what I would hope would be close to zero implementation overhead being that the “bones” should already be in place from other dual colored storms.