Drift

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someblokecalleddave

someblokecalleddave

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So in this thread I want to see if between us we can somehow un-ravel the physics behind Drift and turn all the esoteric langauge into something the Layman (Me) can make sense of. What I'd like to end up with is something along the lines of this hypothetical list as below......................

Key components required to bowl a Leg Break and produce good drift.

1. The ball needs to be angled towards 50'
2. The ball needs to be rotating at 7 RPS
3. The axis needs to pointing downwards at 'x' degrees
4. The ball needs to be travelling 47 mph
5. A high prominent seam increases/decreases the amount of drift
6. The ball needs/needs not to be worn and rough

I know some of you out there are good at physics and those of us that are useless would like your help in deciphering all the lingo into something a little more palatable. Part of the process I think must be to collate as much of the data that is out there and put the sources and links in here and hopefully over the next few weeks or months we'll be able to produce something we can all understand without having to do a degree in Physics.

Here's the first link from Shrek posted in the Top-Spin thread http://vaughan.roberts.name/sites/default/files/Physics of bowling cricket balls - Part5.pdf it's not one I've seen before and the source for some of it was indicated by SLA - Brian Wilkins - 'The Bowlers Art'. Again not a book I've read or even seen before. As we go through the process, may I suggest that when we talk about the direction that the seam is pointing we use the clockface method -
307344_1256576077284_282_280.jpg

So a standard leg break would have its seam and spin direction pointed towards 52' and a Top-Spinner 0' and so on. I'll have to come up with some way of illustrating the axis direction as that's going to be important too I think.
 
Pure topspin will dip
Pure backspin will "float" or "carry"
Pure corkscrew spin (ie legspin) will only drift at the end of the flight as the ball descends
Pure sidespin ("flying saucer") will swerve sideways for the entire flight

A combination of these spins will produce a combination of the effects. There is no real "ideal" combination, its a case of swings and roundabouts really.

The harder you spin the ball, the bigger the effect.

Ideal speed for a spinner in my experience is between 45mph and 65mph, but I have no evidence for that. Certainly you can see the effects are still very visible at 90mph if you watch baseball pitchers throw their different pitches.

A "curveball" has topspin
A "fastball" has backspin
A "sinker" or a "slurve" have sidespin (in opposite directions)
A "slider" has corkscrew spin (basically a 90mph offbreak)
 
SLA said:
Pure topspin will dip
Pure backspin will "float" or "carry"
Pure corkscrew spin (ie legspin) will only drift at the end of the flight as the ball descends
Pure sidespin ("flying saucer") will swerve sideways for the entire flight

A combination of these spins will produce a combination of the effects. There is no real "ideal" combination, its a case of swings and roundabouts really.

The harder you spin the ball, the bigger the effect.

Ideal speed for a spinner in my experience is between 45mph and 65mph, but I have no evidence for that. Certainly you can see the effects are still very visible at 90mph if you watch baseball pitchers throw their different pitches.

A "curveball" has topspin
A "fastball" has backspin
A "sinker" or a "slurve" have sidespin (in opposite directions)
A "slider" has corkscrew spin (basically a 90mph offbreak)
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Does that then mean that any ball bowled with the seam presented at 52' (See above) and spun hard in excess of 45 mph is going to drift towards leg at the end of its flight - is it that simple?
 
someblokecalleddave said:
Does that then mean that any ball bowled with the seam presented at 52' (See above) and spun hard in excess of 45 mph is going to drift towards leg at the end of its flight - is it that simple?
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Unless there is a 50mph gale blowing in the other direction, then yes, as far as I understand it, it is that simple.
 
someblokecalleddave said:
Does that then mean that any ball bowled with the seam presented at 52' (See above) and spun hard in excess of 45 mph is going to drift towards leg at the end of its flight - is it that simple?
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Exactly - Simple as that. That is also the reason why all spinners are taught to try and keep the seam pointing towards the slips. (which would roughly be 52-54 on the clock). Even the pdf that I posted in the topspin thread earlier talks about a variety of "drift and swerve" as two different mechanisms to achieve the same end - i.e sideways movement in air. And it mentions that keeping the ball roughly 52-54 (15 degrees to flight) reaches an agreeable compromise between Dip, swerve and drift.

Spin it as hard as you can, bowl over 60 kmph, keep the ball spinning on the seam and towards 52, the only thing you then have to worry about is your control. Ain't that simple ;)
 
I think the main advantages of understanding the causes of dip, float, drift, and swerve aren't to try and find "the perfect ball", but are instead extremely useful tools in being able to vary your delivery slightly from one ball to the next.

You don't actually need extravagant variations like googlies and flippers to get a good batsman out, if you can just keep it on a length, spin the ball hard, and change the flight slightly from ball to ball you will soon get the better of him.
 
All of the good batsmen I know tell me that the hardest thing about facing a good spinner is not the turn off the pitch but judging the length correctly. This is the main reason why when people have asked me if I think they should sacrifice spin over accuracy I tell them absolutely not. The effects of hard spin on the ball in flight makes judging the length correctly a very difficult thing to do.

And like SLA says you come to realise that small and subtle variations are what gets the batsmen second guessing and that is the state of mind you really want him in.
 
Okay all well and good so far, but now offer and explanation as to why we see it so little in Pro Wrist Spinners bowling - Youtube etc. Watch countless Warne deliveries and you'll see that drift occurs at most 25% of the time? If it's such a important aspect that creates real problems for the batsmen - why is it seen so infrequently?
 
Hmmm. I can't say I've ever really noticed that. My recollection of watching Warnie is that every ball seems to drift and turn a ridiculous amount.
 
I've been watching Alfridi and Tahir over the last couple days and not seen any noticeable drift, Tahir was bowling with a scrambled seam with fairly limited revs put on the ball.
 
Saradhy Krishnan said:
Warne mostly used to get considerable amount of drift. He always used to say that the amount of drift that you get is with how much amount of revolution you put on the ball, as long as the seam position is perfect.And you are absolutely right the speed also is a key factor if you bowl it too slowly the Magnus effect wont take place

cheers
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Yeah that is true although you can still get a lot of magnus effect bowling a lot slower than warne. If you can really put some revs on it.
 
Kiran Rajkumar said:
Terry Jenner says that you need to have a perfect body alignment to get consistent drift and Warne had it.
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I think there's a lot of truth in this. If you think about it. Warne, who we're kind of looking at as an exemplar case of an exponent of Drift was under Jenners charge or went to him when he was struggling it seems. It would therefore make sense that Jenners advice is sound albeit very simplistic and perhpas needing to be broken down into something we ( or I) can make sense of and put into practice. Over on siliconcoach I've had some on-line tuition from Liz and Tony and this is mainly looking at body alignment and working with that area of my bowling and it's only since then have I begun to see any Kieran, so I think Shreks onto something with this.
 
someblokecalleddave said:
Okay all well and good so far, but now offer and explanation as to why we see it so little in Pro Wrist Spinners bowling - Youtube etc. Watch countless Warne deliveries and you'll see that drift occurs at most 25% of the time? If it's such a important aspect that creates real problems for the batsmen - why is it seen so infrequently?
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It's a curious answer I know, but I think one-day cricket is to blame for this. I think spinners of recent times have grown up with a dot-ball mentality that has led most of them to bowl a lot flatter with less spin, and this flatter trajectory just kills drift stone dead. The two biggest drifters of the ball I've seen are Warne and MacGill, and they both have massively loopy actions at seemingly impossibly high speeds that rely on an element of topspin to bring the ball down short enough, which is their way of maximising the time the ball spends travelling downwards before pitching - this part of the flight is the key to a big-drifting leg-break.
(Graeme Swann is the one off-spinner I've seen get significant drift and he has a rather unusual grip which indicates he favours top-spin, so perhaps he's using the same top-spin trick as Warne and MacGill)

Add to that, in one-day matches there's less time for the ball to deteriorate than in First Class cricket, and a rough ball is a big help when you're aiming to create drift. The friction of the air on the ball is what creates drift, so a rougher ball with more drag will drift more.

In Warne's case I think the reason you don't see him drifting more is because what you see of his bowling is highlights rather than a full spell, so you see a disproportionate amount of the variations - usually flippers or sliders, which won't drift much - rather than all the drifting stock leggies he bowls in between.

As for Jenner's comments, I think he's talking more about bowling drift that is useful rather than just drifting the ball. What Warne was brilliant at was getting the ball to drift AND still having control over where the ball lands, and this does require a highly repeatable action and excellent control of how much the ball spins. Anyone who can spin the ball hard enough and bowl it fast enough with the seam the right way can get drift, but if it's not consistently landing where they want it to it won't be much use. Warne's total control was the thing that allowed him to get really big drift, while a bowler with less control would have had to sacrifice drift for greater accuracy or, like Macgill, simply accept that he'd be bowling a 4-ball every over, and captains aren't very fond of 4-balls.
 
Spiderlounge said:
It's a curious answer I know, but I think one-day cricket is to blame for this. I think spinners of recent times have grown up with a dot-ball mentality that has led most of them to bowl a lot flatter with less spin, and this flatter trajectory just kills drift stone dead. The two biggest drifters of the ball I've seen are Warne and MacGill, and they both have massively loopy actions at seemingly impossibly high speeds that rely on an element of topspin to bring the ball down short enough, which is their way of maximising the time the ball spends travelling downwards before pitching - this part of the flight is the key to a big-drifting leg-break.
(Graeme Swann is the one off-spinner I've seen get significant drift and he has a rather unusual grip which indicates he favours top-spin, so perhaps he's using the same top-spin trick as Warne and MacGill)

Add to that, in one-day matches there's less time for the ball to deteriorate than in First Class cricket, and a rough ball is a big help when you're aiming to create drift. The friction of the air on the ball is what creates drift, so a rougher ball with more drag will drift more.

In Warne's case I think the reason you don't see him drifting more is because what you see of his bowling is highlights rather than a full spell, so you see a disproportionate amount of the variations - usually flippers or sliders, which won't drift much - rather than all the drifting stock leggies he bowls in between.

As for Jenner's comments, I think he's talking more about bowling drift that is useful rather than just drifting the ball. What Warne was brilliant at was getting the ball to drift AND still having control over where the ball lands, and this does require a highly repeatable action and excellent control of how much the ball spins. Anyone who can spin the ball hard enough and bowl it fast enough with the seam the right way can get drift, but if it's not consistently landing where they want it to it won't be much use. Warne's total control was the thing that allowed him to get really big drift, while a bowler with less control would have had to sacrifice drift for greater accuracy or, like Macgill, simply accept that he'd be bowling a 4-ball every over, and captains aren't very fond of 4-balls.
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Yeah - topspin really does have that magic effect on accentuating the effects of sidespin - it both creates dip, which means a greater portion of the flight is vertically downwards and so accentuates drift, and it also reduces the velocity difference between the underside of the ball and the ground, meaning that the ball can grip more and will turn more as a result.

Hence the optimum spin angle for getting both big drift and big turn isn't actually 90 degrees to the direction of the pitch - its probably closer to 45 degrees forward.

Get that angle right and give it a serious rip, and you won't go far wrong. That's pretty much all Warney did.
 
The 45 degree ball e.g. 52' seam angle does seem to be the optimum ball to give you drift and dip, but this is at odds with Woolmers analysis in his book.

Interesting that Jenner says 'Very few wrist spinners are able to get the ball to drift'.
 
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