Part: Part Five - Betting Before the Flop

Opening by position

Pre-flop
Blinds 100 / 200Pot 300 (1.5 BB)COK10 25,000 (125 BB)YOUfolded to youSB 25,000 (125 BB)posts 100 (0.5 BB)BB 25,000 (125 BB)posts 200 (1 BB)D

It folds to you on the cutoff with K♠T♠.

Folded to you on the cutoff with K♠T♠. Best?

WhyOnly the button and two blinds are left to act, so K-T suited comfortably clears the bar here - it makes strong top pairs, flushes, and straights, and few players get to see a flop with position on you. From under the gun with eight seats behind, the exact same hand is a fold; the seat, not the cards, is what changed.
What happensYou raise to 500 (2.5 BB) and only the big blind defends. Pot: 1,200 (6 BB). You reach the flop heads-up and in position - the scenario a late-position open is built to create.
Flop
Heads-upPot 1,200 (6 BB)K84COK10 25,000 (125 BB)YOUtop pairBB 25,000 (125 BB)Big blindchecksD

Flop K♦ 8♣ 4♥ - top pair on a dry board. He checks.

Top pair, dry board, he checks. Best?

WhyK-8-4 rainbow gives worse hands little to draw to, but plenty of second-best pairs and stray gutshots still exist - your top pair wants their chips now, before a scary turn shows up. Betting also keeps the initiative you took pre-flop.
What happensYou bet 700 and he folds. Collecting small pots like this uncontested is most of what a positional open actually earns - it won't often flop into a monster, and it doesn't need to.
King-ten suited clears the bar on the cutoff but not from under the gun - same cards, different seat, different answer. Anchor every opening decision to how many players still act behind you.

The button is the most profitable seat, so your opening range should tighten as you move away from it and loosen as you approach it - how many players still have position on you sets the bar to raise first in, not card strength alone.