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

Red zone: position widens your jam

Pre-flop
Blinds 400 / 800 (100 ante)Pot 2,100 (2.6 BB)Your M = 4 • Red zoneBTNK♣8♦● 8,400 (10.5 BB)YOUfirst to actSB● 16,000 (20 BB)posts 400 (0.5 BB)BB● 16,000 (20 BB)posts 800 (1 BB)D

Red zone (M 4). It folds to you on the button with K♣8♦.

Red zone, folded to you on the button with K♣8♦. Best?

WhyOpen-shove. Position dramatically widens your Red-zone shoving range - on the button with only the blinds behind, K-8 offsuit is a clear jam. The dead money (blinds plus antes) and fold equity make it profitable.
What happensYou shove; the blinds fold.  Late position widens the jam.
Your push-or-fold range depends heavily on position: with only the blinds left to act, you jam a much wider range than from early seats.

In push-or-fold, widen your shoving range as your position improves - the button jams far wider than under the gun.