rules on catching

I've been thinking recently about the definition of catching, the 'strip' call and simultaneous catches.

According to the 2009 WFDF rules of ultimate

"12.1. A player “catches” the disc by demonstrating sustained control of a non-spinning disc."

This would be a little after a receiver first touches the disc. Even after they touch both the top and bottom surfaces of it, it would probably still be spinning (and the receivers hand spinning with it), for just a moment.

Simultaneous Catches

I once thought that the rule about simultaneous catches was only there to help sort out disputes about who caught a disc first.

12.5. If offensive and defensive players catch the disc simultaneously, the offence retains possession.

Two different things happening 'simultaneously' is unlikely, right? When you look in super slow motion, one player will always get to the disc microseconds before the other. But getting to the disc is not catching it. Even after your hand is touching both the top and bottom surfaces, it still spins a little. And if both players first touch the disc in quick succession while both attempting to catch it, the moment when the disc stops spinning is the moment both players catch it simultaneously. I don't think a simultaneous catch is unlikely after all. It's a sensible rule to include. 

'Strips'

It often happens that an offence player tries to catch the disc and a defender tries to D it at the same time. Considering that the catch doesn't technically happen until "sustained control of a non-spinning disc" is demonstrated, I think that often, those strips that, from afar, look like a good D are usually just that, a good D.

Now from afar, you don't have the best perspective, so next time I call strip, keep quiet about this post!

Usually if after a disc is caught, a defender tries to swat it away and hits only disc, it should be fairly obvious it was a strip (either that, or the first catcher has a good enough grip to hold onto it).

Conclusion
These 2 points together mean that as a defender, if it's close, you don't want to try to catch it a disc, but rather knock it away! Even if you touch the disc first when trying to catch it, you might lose it on a simultaneous catch, whereas if you try to knock it away, you can still manage it legitimately even if the offender touches it first.

Although, experience has shown me that catching discs isn't a bad habit to have. Swatted away discs tend to get caught by someone else.