Majoru Oakheart
Adventurer
This is actually very similar to the Numenera skill system. In it, you assign a number between 1 and 10 and rather than add modifiers to your d20 roll, you use your skills to lower the difficulty of the skill. If it reaches 0 you auto succeed. Otherwise you need to roll 3 times the(now lowered) difficulty or higher on a d20.I still think they should go way way back and use this skill system: https://www.wizards.com/dnd/article.aspx?x=dnd/4ll/20110816
The system Mearls proposed back in 2011 just gives you ranks of skills from 0 to 6. If something's difficulty is at or below your rank, you just auto-succeed. If something's 1 rank higher, you'd make an ability check (DC 10) to pull it off.
I'm guessing Monte go some of his ideas from extremely early versions of the D&D Next playtest. Or at least ideas they were tossing around for D&D Next.
I've always suspected that Monte left partially because he wanted to change things more than the rest of the team was willing to. I suspect we have the current skill system because someone on the team suggested it would be too jarring to change the mechanic that much from the system used in 3e and 4e.