I recently switched to this build and I can say with full confidence that this is by far superior to ANY UR Delver build
in the current meta.
The deck:
4 Delver of Secrets
4 Lightning Bolt
4 Brainstorm
4 Daze
3 Chain Lightning
4 Force of Will
4 Volcanic Island
4 Scalding Tarn
1 Flooded Strand
1 Polluted Delta
2 True-Name Nemesis
1 Wooded Foothills
1 Misty Rainforest
1 Mountain
2 Island
4 Ponder
4 Wasteland
2 Gitaxian Probe
2 Young Pyromancer
2 Snapcaster Mage
3 Grim Lavamancer
3 Stifle
4 Surgical Extraction
1 Red Elemental Blast
2 Flusterstorm
1 Forked Bolt
2 Abrade
1 Price of Progress
1 Blood Moon
1 Izzet Staticaster
1 Divert
1 Spell Pierce
I played 2 leagues, went 3-2 and 5-0 before I realized that this deck was absolute gas and I needed to gather data. So today I played 3 more leagues and kept the data:
https://docs.google.com/spreadsheets...it?usp=sharing
Just to give a little background, I've played all the flavors of delver, was really good at RUG maybe 4/5 years ago I play on and off and recently came back to playing magic again.
What makes the deck good:
Grim Lavamancer
In a meta full of Deathrite Shaman, Grim Lavamancer is king. In Grixis mirrors where you both have DRS, its a subtle dance for who gets mana/life. With Lavamancer, there's no dance, they either kill the lavamancer or lose their whole board.
I used to board 1 Lavamancer in my Grixis Delver deck just for this reason.
Basic Lands
Not getting wastelanded out of the game is a great feeling. It does inconvenience you sometimes when you brainstorm and you look at your other land and you wish it was something else. But you know whats more inconvenient? Not having lands.
Stifle
This hits a lot of stuff besides fetch lands.
The deck plays like RUG(the stifle build) except you have basics and grim lavamancers. You're losing Tarmogoyf and Nimble Mongoose and neither is very good right now. You have more reach instead thanks to chain lightnings & Snapcaster Mage.
On the differences to the prowess builds, when playing the prowess creatures, I often had situations where you cant really trigger prowess on your turn(hand full of counters) or you draw them late and they're garbage.
On grixis, losing Deathrite is pretty big, but the tradeoff is Lavamancer, which beats opposing Deathrites. Gurmag Angler is also a card that is hard to stop, unless you have a live Lavamancer, in which case its merely a bolt away from dying. Your only real problem is TNN, which you also play, and you play stifle/daze/waste so getting to resolve a 3 mana spell should be pretty difficult. It does hurt the reanimator matchup so I play 4 surgicals in the side. That said I've played 4 BR reanimator matches and lost only 1. Dredge should be kinda bad though.