Node Locking

What Is Node Locking?

Node locking is an advanced solver technique where you fix (lock) an opponent's strategy at a specific decision point in the Game Tree, then re-solve to see how the optimal counter-strategy changes. Instead of computing the equilibrium where both players play perfectly, node locking answers the question: if my opponent makes this specific mistake, what is the most profitable way to respond?

Why Node Locking Is Powerful

Pure GTO play is the unexploitable baseline, but it leaves money on the table against opponents with identifiable leaks. Node locking bridges the gap between GTO and Exploitative Play by letting you quantify exactly how much extra profit each exploitation generates. You can see the precise strategic adjustments that maximize EV against a specific opponent tendency.

Common Node Locking Applications

• Over-folding opponents: Lock their folding frequency higher than GTO, then observe how the solver increases bluffing frequency
• Calling stations: Lock their calling range wider than GTO, then see how the solver removes bluffs and bets thinner for value
• Passive opponents: Lock their raising frequency to zero, then watch how the solver adjusts bet sizing and checking ranges
• Nit 3-bet ranges: Lock their 3-bet range to only premiums, then see how the solver expands opening and flatting ranges

Practical Example

You suspect a regular opponent folds to river bets 70% of the time instead of the GTO-prescribed 50% against pot-sized bets. You node-lock their river defense to 30% continue, then re-solve. The solver dramatically increases your bluffing frequency on the river, often adding hands that would normally check back. The output tells you exactly which hands become profitable bluffs against this specific leak.

Node Locking in Practice

Solver+ supports full node locking functionality, allowing you to test exploitative adjustments against any opponent profile. For a step-by-step guide to using node locking and other advanced solver features, read How to Use a Poker Solver Effectively. Node locking is the single most practical solver technique for translating study into real-world profit.