Slipping Water during the arm pull ?

I have recently become aware that i was slipping water during the underwater pull. This was happening because I have unusual flexibility in my hand. I can lay my hand flat on a surface and raise my fingers up to 45 degrees while keeping my palm flat. They will bend back to 90 degrees from the palm with some pressure. I had read "Colwin's" info on hand position in "breakthrough swimming". This discusses whether the hand should be cupped or flat for good propulsion during swimming. I was also watching a sequence in "New ideas in free & back" by "Marty Hull" where he has the swimmers deliberately " SLIP " water during the pull. They did this by allowing the hand to bend back from the arm. When i was next in the water I checked my hand position and during the pull my fingers bent back quite far, even though my palm was still at 90 degrees to the water. This allowed the pressure against the water to " flow away". New fluid dynamics research has shown that the water pressure flows from the fingers up the hand and to the forearm. If the fingers are not slightly cupped then this flow cannot happen as effectively and pressure against the water is lost. I realised that I was swimming with only my palm (and forearm) providing propulsion. I corrected by making a real effort to slightly cup my fingers and instantly I held more strongly onto the water. My stroke count dropped by 1 - 2 strokes per 25m and my time was 5% less. I have a meet coming up and I will see then whether my race times will drop after making these changes. Has anyone else noticed this effect while they are swimming ?