This could be integrated with the ignominious history provided at the end of each mortem.
e.g. instead of '50 were killed':
13 were killed by hellspawn.
1 was killed by something unknown.
7 had luck that proved fatal. (lava lever/phase instadeath/killed from 100%/dead on stairs or invul/zerk)
6 didn't make good use of their resources. (dying with tons of medpacks/forgetting about armor/on a damage floor with an envirosuit, or without wearing boots in their inventory beforehand/with a fully-loaded unique or BFG in their inventory/maybe running dry of ammo in non-MAc)
7 didn't read the thermonuclear bomb manual. (mark of impulsiveness)
9 cocksure bastards got in over their heads. (maybe running out of ammo/dying within x turns of a special level)
4 couldn't figure out when to run. (100% kills until death level, killed by last enemy on level which was M/V/R/died with a homing phase in a dangerous demon cave or similarly bad place)
...
And 3 couldn't handle the stress and committed a stupid suicide. (mark of clumsiness, recklessness, idiocy)
Of course there should be some sort of one-liner in the 'current' mortem to tell you which statistic this YASD boosted.
I've earned remarkably few, myself, though I only have a few dozen mortems.