Part: Part Nine - Inflection Points: M, Q & the Zones

A short blind battle

Pre-flop
Blinds 400 / 800 (100 ante)Pot 2,100 (2.6 BB)Your M = 5 • Red zoneSBK♦7♦● 10,500 (13.1 BB)YOUfolded to you, blind vs blindBB● 16,000 (20 BB)posts 800 (1 BB)D

M 5, on the Red/Orange border. It folds to you in the small blind, heads-up against the big blind, with K♦7♦.

Short, folded to you in the SB versus the BB, with K♦7♦. Best?

WhyOnly the big blind can call, and the blinds plus antes are a real chunk beside your short stack, so a jam profits with a huge range - K-7 suited well inside it. A limp or min-raise just builds a pot you'll play out of position with no fold equity; the shove is cleaner, and it's still correct even on the times he wakes up with a hand.
What happensThis time the big blind snaps it off with A-9 and holds - you're out. The jam was still right: a wide blind-vs-blind shove prints over the long run, and one called-and-lost hand doesn't change that.
Short and blind-versus-blind, you jam a very wide range because the dead money and single opponent make it profitable - even though it won't always win. Judge the decision, not the river.

One opponent, dead money already in the middle, and a stack too short to play post-flop - blind-versus-blind, that's the recipe for a very wide shove.