IPT

Gear ratio tells you how many times the spool spins. IPT tells you how much line that actually moves, which is the thing you care about. A 6.2:1 reel with a large spool can retrieve faster than a 7:1 reel with a small one, because each rotation of a wider spool picks up more line.

Manufacturers print IPT on the box next to the ratio, usually somewhere between 20 and 40 inches for freshwater baitcasters. It also shifts as you fish: a full spool has a bigger effective diameter than one halfway down, so your retrieve genuinely slows through a long cast.

For most people this is a spec to check once when comparing two reels across brands, then forget.