PFR (Pre-Flop Raise) is the percentage of hands in which you raise before the flop: opening, 3-betting, 4-betting or raising over limpers. It measures how aggressive you are preflop.
How it's calculated
The healthy ranges on the side are guidelines for NL Hold'em cash games with 100 bb stacks, the same ones Flopmortem compares your game against. Use them to spot big deviations, not as an exact target: they depend on the table, your opponents and your style.
How to read your PFR
In no-limit cash games, the initiative is worth money: the preflop raiser often wins the pot with a c-bet, even without hitting. That's why a good player's PFR sits close to their VPIP.
A low PFR with a normal VPIP means you get in by calling too often: you trade hands that should raise for calls and give up your opponents' folds. A very high PFR usually comes from opening ranges that are too wide from early position.
If your PFR is out of range
Too low
You rarely raise preflop and call a lot instead: you give up the initiative and your opponents' folds. Swap calls for raises with your strong hands and your best bluffs.
Too high
You raise too much: check that your early-position opens aren't inflated.
How many hands you need to trust it
Flopmortem doesn't flag your PFR as a leak until it has at least 100 opportunities. From there it calculates it with its 95% confidence interval: if the whole interval falls outside the healthy range, the leak is confirmed; if only the measured value is outside, it's a trend. The guide how many hands you need to trust your stats explains it.