Strokers tend to be a little squarer to the line. Their shoulders are closed (parallel with the foul line), they usually stay behind the ball and have backswings level with or below the shoulders. Typically play more to the right side of the lane (for righties), first, second, third arrows. Steve Jaros, Brian Voss, Norm Duke. If you're watching the show on Sunday (you are, aren't you?), Jack Jurek, if I remember right.
Crankers usually have more open shoulders, higher backswings, and their hands are usually inside the ball at the height of the backswing. They usually play the big hook, starting around the third or fourth arrow or further left. They plant their foot and often have later timing which lets them generate a lot of leverage to turn the ball. May have a big snap at the release point to generate even more revs and speed. Again, if you're watching the show, Tommy Jones is a textbook cranker.
Tweeners have some elements of both. Shoulders maybe not quite so open, maybe come up the back more than crankers. But with a more cupped wrist and snappy release which generates more power than strokers. Sometimes called power strokers. Pete Weber, Chris Barnes, and Mike Machuga are who I think about for tweeners.
SH
