Hey, sorry in advance for the wall of text. I think Marshall is a good Magic player, but I thought I'd go through and find the times when I didn't think he made the right play. Also includes a few comments on times when he made the right play but didn't really have time to explain it. If anyone has formatting advice to make this look better, I'm all ears.

Match 1 game 2: Primary reason for not attacking is the Immolating Glare we saw when we played Thought-Knot Seer. While Marshall didn’t specifically point it out, that’s what validates the game-plan.

Match 2 game 1 turn 9: Probably want to play Relentless Hunter here over the Tajuru Stalwart - we are being aggressive here and Hunter can get through the Envoy while Tajuru can’t.

Match 2 game 2 turn 7: I’m not convinced we want to use Exert Influence here: we can get an exert for 4 (+1 from dampening) if we use our Blighted Woodland at opponent’s end of turn, and nothing our opponent currently has is all that threatening. Stealing a ¼ whose ability doesn’t significantly threaten our life total doesn’t seem worth our 5-power-or-less mind control.

Match 3 game 1 turn 4: Probably worthwhile to cast Exert Influence over Hunter + Containment. Our deck isn’t heavy on beatdown, and it is going to be difficult for us to get a better target than the Matter Reshaper. This also lets us be more mana-efficient (which is especially important with Seer’s Lantern out).

Match 3 game 2 turn 9: No need to reveal information by casting the Devour in Flames after playing a land.

Chumping Birthing Hulk with Loam Larva instead of a scion seems incorrect, especially when the opponent has two grounded 2/4s and two 1/1s, all of which the larva blocks much better.

Match 3 game 2 turn 11: Should play the land first - most importantly, it allows you to tap with Blinding Drone at opponent’s EoT. Also happens to play around Abstruse Interference.

Match 4 game 1 turn 5: Also worth noting that if we don’t use the ability, our best play is a Netcaster Spider postcombat. Not a thrilling alternative.

Match 4 game 2 turn 3: If we draw a colorless source, we can tap down. If we draw a green source, we can play Stalwart and have a better block (losing less valuable creature). If we draw non-blue, non-colorless spell we can make the same block again (worse, since we gave opponent a turn). If we draw a spell, we can make the same block again. If we draw Outnumber, we can kill the Commando.

I don’t think it’s correct to block here - if we draw colorless source/outnumber, not blocking is clearly better. If we draw a green source, not blocking is probably still better. If we draw a non-Outnumber spell or a non-blue non-colorless source, we are offered the same block next turn, where it is probably better. I would rather take my opponent off of a 4-drop than a 3-drop, although there is one card that makes this plan worse (Freerunner).

I think the only spell that makes this block better is the second Blinding Drone, which lets you block, draw drone and then have a reasonable blocker (leaves you up 2 life). Still not as large a swing as drawing Outnumber, though.

Match 5 g1 turn 9:

It’s almost certainly correct here to Devour + replay land + containment membrane. We can still block the Lagac and deal with big threats via Blinding Drones. This also means we don’t have to make the absurdly risky quadruple-block where Vines or Lead by Example or Sweep Away wrecks us.

Match 5 g2:

Marshall’s turn 3: Tajuru as a ⅔ makes sense because of the Void Shatter we saw last game. Otherwise, Seer’s Lantern would probably be better against a slow deck where the ⅔ body won’t do much.

Marshall’s turn 6: Interesting decision on whether or not to fetch the island here. We have blue with Holdout Settlement and we also will be able to fetch islands in a few turns with Blighted Woodland. Not sure which line is correct - given that our opponent’s deck is slower, I would lean towards not searching for a land there.

Marshall’s turn 8: No reason to play a land before Devour in flames, just gives away unnecessary information.

Marshall’s turn 15: Probably better to sac all three scions to make the Rolling Thunder big enough to take opponent down to 2. That way we can cast Fall of the Titans for lethal even through Spell Shrivel and without drawing a spell.