Well, if you crunch the numbers the perfectly average draw nets 10.133 aether for us on turn 4 (which is more than enough with upped fractals) and 10.2 aether for them on turn 4 (which is a bit low to avoid standard deviation). You'd be surprised how often 16 pends get the job done. But even though our average draw beat theirs, our deck was a bit more likely to suffer from bad draws. That ended up leading to this.
That again shows their odds are better. An easier way of illustrating it is with a median rather than an average, since the difference between 4 and 5 pends is night and day. If your average is 10, near half the time you'll be a full 2 turns off from 10 because you drew 4 pends (you have a chance to draw the 5th pend on turn 3 thanks to upping Fractals, which is why it's only "near" half the time).
If an Aether mark deck draws fewer pends than what's perfect, it's more likely to be only one turn from 10 instead of 2, and if it's 2 turns off it'll have about as much Gravy as you but it will likely have played creatures 1 turn before you and a heavy Gravy draw can even be enough to win them the game (the no-impact-Fractal-games). For them the average is much more relevant because hitting 9 is fine thanks to having an Aether mark, while a full pend build skips the odd numbers unless it draws the 5th pend on turn 3 (a pend after that only nets you more Gravy). In other words, you put the pend draws on a clock for the early turns that delays for slightly more than theirs will with a non-ideal draw, and as we all know 1 turn is all it takes to lose.
Besides that we also have the low number of Fractals, as mentioned. Luckily this is a quanta mirror, so you having one less creature doesn't matter; you could always Fractal his creatures regardless.
And don't worry. I've probably played more than anyone else alive with everything from 10-20 pure pend builds. No risk of surprise here. 16 is my preferred number for Fractal rushes too, but one of the first things I unfortunately had to admit was that an in-element Fractal deck will have the early-game advantage and more consistent draws, which entices me to play some control cards unless I wanna gamble on me getting an ideal draw every time (and that's keeping in mind that their odds of having an ideal draw are not lower than mine, so that's a bad gamble for me). With some upped pends, it becomes more enticing, but it's still playing with the devil. In War you might just have to do that though.
