Experimenting with less depth for the purpose of staying tight, cf. e.g. Idalberto Arranda: http://www.youtube.com/watch?v=VcEsmhVag1c and Vasiliy Polovnikov: http://www.youtube.com/watch?v=ExYd74SEZfE
I don't think it was deep enough; a few of them don't even look parallel.
Let me know what you think.
