Straddles before the flop

How a straddle changes the pot, the positions and every preflop range, from the opens to the blinds and the straddler's own defence.

Rail analyses one straddle only: a single 2bb straddle from the seat left of the big blind, 4-6 handed, near 100bb. Other straddled pots are taught in words.

Conceptual: Rail does not analyse this spot yet, so this lesson teaches the idea without a graded drill.

In this lesson

Explain how a straddle changes the pot size and who acts last before the flop.
Adjust opening and 3-bet ranges seat by seat in a straddled game.
Play the small blind tighter and defend the straddle like a deeper big blind.
Expect more multiway pots when there is a straddle.

Read first: How much to open, online and live · Advice, not a lock: every lesson opens.

Concepts used: Raise first in (RFI), Blind defence

What a straddle changes

A straddle is a voluntary blind of 2 bb posted before the cards, usually under the gun. The pot starts at 0.5 + 1 + 2 = 3.5 bb, the straddler acts last before the flop, and every stack is worth half as many of the new big blind: 100 bb is 50 straddles. The game plays like a shallower one with more dead money in the middle.

Opening into a straddle

Opens scale with the straddle. An open to 6 bb risks 6 to win the 3.5 in the middle and needs everyone to fold 6 / 9.5 = 63.2% on its own — about what 2.5 bb into 1.5 bb needs without a straddle. The positions shift by one: the seat after the straddler is the first to open.

Blinds and antes in the middle3.5 bb

Your open (chips risked)6 bb

How often they fold63%

Alpha: folds needed: 63.2%
EV if it never wins when called: -0.01 bbLosing

A 6 bb open into a straddled pot of 3.5 bb.

Defending the straddle, and the blinds

The straddler facing a 6 bb open with everyone else folded calls 4 to win a pot of 9.5: the call needs 4 / 13.5 = 29.6% of the pot after it. He defends like a big blind, with position on the blinds but less behind in straddles. The small blind is out of position against everyone and plays tighter; straddled games also see more callers, so more pots go multiway.

Rail has one straddle chart set: 6-max at 100bb with a 2bb straddle from UTG, opens to 5bb (2.5 straddles). The exercise below paints its opening ranges. Other straddles (a button straddle, a re-straddle, other depths) are still taught in words.

Rules of thumb

Count the stacks in straddles: 100 bb is 50.
Scale the opens with the straddle and price them the same way.
Defend the straddle like a big blind with less behind.

When they break

A table where everyone calls opens is a multiway game: value over steals.
A button straddle changes who acts last again: count the positions afresh.

Practice

The lesson is mastered when every exercise below that Rail can grade is passed. Missed items come back later as review cards.

Exercise 1

Pass: 5 of 6 right

Six opens into blinds and straddles: how often must everyone fold?

Exercise 2

Pass: 4 of 5 right

Five calls to price against a bet: how much equity do they need?

Exercise 3

Pass: 2 of 4 right

Paint a seat's opening range in a straddled 6-max game at 100bb.