MOCS winning deck: R/w (/b) Burn

Anssi A managed to take down the (rescheduled) MOCS last weekend with an interesting deck:
//21
4 Temple of Silence
4 Sacred Foundry
4 Temple of Triumph
9 Mountain

//10
4 Rakdos Cackler
1 Firedrinker Satyr
1 Ash Zealot
4 Chandra's Phoenix

//29
4 Shock
4 Chained to the Rocks
4 Boros Charm
4 Lightning Strike
4 Magma Jet
4 Skullcrack
2 Toil/Trouble
3 Warleader's Helix

Sideboard
2 Anger of the Gods
1 Peak Eruption
2 Mizzium Mortars
2 Young Pyromancer
4 Boros Reckoner
2 Spark Trooper
2 Toil/Trouble

The deck as constructed is a pretty strange looking one. 21 lands, 10 creatures, 25 burn spells, and 4 Chained to the Rocks(?).

The way the deck is built, it actually makes a lot of sense. Given the presence of 4 Magma Jet and 8 scrylands, you can avoid getting flooded or screwed more often than not, I would imagine. Creatures are actually a liability at the moment, so Anssi A picked ones that go way under Supreme Verdict or have haste.

I also don't quite understand the sideboarding plans for the deck. But I plan to try to learn it this week.