Post by Someblokecalledave on Sept 5, 2012 18:06:34 GMT -5
Questions, suggestions, observations and theories on Drift.
As I recall on the drift thread there, the concensus was that most of us felt that drift was achieved more frequently with the seam presented at 45 degrees as opposed to 90 degrees as cited in Bob Woolmers explanation of Woolmers ball of the century. As we know and this is backed up with Stuart Macgills analysis of my bowling elsewhere in the forum, it's not entirely down to the seam presentation. There's obviously more to discuss...
Post by cricketdudeguy on Sept 27, 2012 7:29:26 GMT -5
thanks for the welcome watched lots of your videos on youtube and they helped a lot how can i get macgill to have a look at my bowling. i find if i dont hold not tense enough it does not spin as much and the same if you hold it to lose.
Post by Someblokecalledave on Sept 28, 2012 18:28:29 GMT -5
With regards to Stuart Macgill, he's signed up to the forum, but as yet hasn't commented since. The thing is he's obviously a bloke with a busy schedule and I'm not really sure whether he has the time to get involved with anything like this and it was increadibly lucky that somehow I made that fleeting connection with him and that he responded. I/We are waiting to see if there's any follow up, but at the same time I don't really want to inundate him with loads of questions and put him off. He did say that he was going to put my vid on his Google + page and he's added me to his 'Circle' on Google + but since then hasn't said or done anything, so that hasn't happened.
We'll just have to wait and see what happens, if I get any news from him I'll let you know, but I don't want to piss him off with loads of requests and questions unless he kind of says or suggests that he's up for it. Maybe have a look at his Google + page and see if you can become one of his friends, but I'm not sure whether that's what he wants to happen? A lot of the content on there relates to his current job and interests connected to wine, and then every now and then he'll comment on cricket in some way, so I'm not really sure what he's up for doing or saying in relation to us?
Post by Someblokecalledave on Sept 29, 2012 18:53:19 GMT -5
That sounds good - has he responded? Good work if he has! My season was awful mate. Right at the start of the season here back in April (I'm assuming you're an Aussie for some reason)?? my younger son who was ten at the time was run down by a car which has smashed his leg to pieces www.mpafirsteleven.blogspot.co.uk/2012/04/joes-progress-5-pictures.html and as a consequence all the practice that I would normally do with him and his older brother, which keeps me fit didn't happen because we've been looking after Joe. That coupled with the rain we had here in the UK which left most of our local pitches un-playable till mid - late June. I never got going. I've had problems with my arm muscles and Piriformis syndrome as well - so as a consequence I've had an awful season. I suppose being 52 as well means I should expect this and I'm kind of thinking that maybe next season - it could be my last...
I've been thinking on drift a little lately. I don't bowl (in ANY format!!!) but I have been able to coach my son a little. He bowls his leggies to me and we experiment with the options he has before him.
Sean's natural (stock) spin is one with the axis of rotation towards backward square leg, so that if the seem is upright, it points towards gully (a "45 degree seem"). This delivery will indeed drift, especially into a headwind or with a wind on Sean's left shoulder during run up.
However, with a scrambled seem on the same axis of rotation, he gets more drift.
I put this down to a tendency for a 45 degree seem to counteract drift in the same way a seem-bowler's angled seem produces an outswinger when he points it toward slips during the delivery.
Post by Someblokecalledave on Sept 30, 2012 10:37:07 GMT -5
Sorry mate, I'm totally baffled by drift and can only talk in terms of the basics, but you now saying that he gets more drift when the seams scrambled - well that just messes with my brain big time!
The general rule though if he is getting more drift bowling in one way or another is somehow isolate exactly what it is he is doing and then work towards being able to pull out that 'Drifter' when required and if you're saying he gets it more with the scrambled ball - well it sounds like you've got it sussed!
I think it must have a lot to do with the Magnus effect of a spinning ball. The seam of the ball when it's moving in a "scrambled" way is having an effect on the ball more than when it's "running true".
Post by Someblokecalledave on Oct 1, 2012 12:45:03 GMT -5
Yeah I've looked at Magnus effect from several different perspectives, I can see why it works with top spin and back-spin - make total sense, but as soon as you present the seam angled at 45 degrees, not of it makes any sense to me anymore, totally baffles me!
that's weird Graeme, the generally excepted view is that it drifts more the cleaner the rotation of the seam on the ball(see Warne for a perfect example huge drift, perfect seam). From personal experience for me the ball drifts a lot more when spun along the seam( nearly twice as much for me) though I usually bowl cross seam so don't get as much drift.
Speaking of drift I had a very weird delivery in the final match of the season, bowling with a ball only a few overs old, I bowled a googly that drifted in rather than away and not small either talking feet, no idea how I did it never bowled anything like it before or probably again, lol.
Last Edit: Oct 1, 2012 18:36:09 GMT -5 by gundalf7
I don't know what it is Gundalf: perhaps something to do with the 2-piece balls Sean uses for practice. The seam is quite prominant. Maybe the ball surface has other characteristics that make it behave that way.
Dave, you'll probably get your head around it more if you consider that the Magnus effect is at its maximum when the ball is moving through the air perpendicularly to the axis of rotation.
Taken at one extreme (top spin) the axis of rotation is horizontal and across the pitch, so the ball is being forced down throughout its flight.
At the other extreme of pure side spin, the axis of rotation is along the pitch and the Magnus effect is not active while the ball is moving essentially parallel to that axis of rotation (ie the first "flat" portion of flight). It is only when the downward component of the flight starts to increase that the magnus effect comes into play in this case. As the vertical speed of the ball increases in the later part of the flight, the ball will start to move towards the leg side (for a RH leggie) because the ball is now moving perpendicularly to the axis of rotation more quickly.
For a 45 degree angle on the seam, there is a component of the Magnus effect working throughout the flight of the ball, but it's higher on the downward path of the delivery than the initial upward and flat path.
Because the downward path of the flight is so vital for drift on a side spinning and 45 degree spinning ball, it's imperitive that a good loopy flight is offered. Without that initial upward and subsequent flatter component to the delivery, there will be no late drift in the flight (there may be constant drift, but it won't be significant nor particularly tricky to handle).
It all comes down to the flow of air ACROSS the axis of rotation.
To get drift from a ball that will also turn off the pitch, there must be a loopy flight so that downward speed has a chance to increase during the delivery. It's the change in vertical speed that alters the drift in the air for a side-spinning delivery.
Post by Someblokecalledave on Oct 2, 2012 18:17:03 GMT -5
Whoa - that sounded almost feasible, thing is it's 12.30 at night and my brains a bit fuzzy, I'll have to copy that into a word file and see if I can get my head round it, the flight and the drop in height is finding some resonance with my brain!!