I used calf ones for years thinking they would tangle less.
Then I got a board with a free ankle strap and found the opposite was true.
The calf ones also have more of a tendency to tangle up both legs if you bail or lose the board under a really big cleanup set.
Spot on OB, I was going to write the same thing. I used one for a while but once it broke went back to the ankle and they tangle less, the calf ones seem to catch everything and as you said getting both legs caught up under a set is not fun.
yep, one off the first questions i asked on here. bb summed it well for me and, after trying both the ankle will be the one least to tangle you when you walk