Drift

Dave! I finally managed to get out to the nets today and i DEFINITELY begun to create drift! It was interesting how i found it. I took five balls down and i'd just bowl them all, go and collect them and repeat etc. I experimented for while with no luck, so i just decided to start practising my different deliveries, so i bowled five leg breaks (no drift) then went and collected them, five sliders (no drift again), Then i bowled five top spinners. Now the very first toppy i bowled DEFINATELY drifted. It completely shocked me. I then just continued to bowl almost complete top spinners (seams maybe 11:30) and noticed the ball drifting quite consistently. These were the things i took note of for you:
1. When i bowled with more side spin, i didn't get any drift. Whether thats because the balls were delivered flatter and thus didn't get as much chance to dip and drift I'm not sure. Thats just the facts.
2. The drift was late, really only occurring when the ball was dipping, which would explain why the toppspinners produced more drift.
3. I pitched them up. To get drift, i really had to toss them up a little so they were landing quite full. too full. I reckon once i get more revs i'll be able to produce drift on a better length ball.
4. Not every single delivery drifted. It may have been because my seam position was poor but i couldn't see the seam anyway.
5. I used an old ball, and the conditions were damp. We had had a bit of rain earlier in the week.

Im so excited hahahaha

Nice work Ben - empirical observations, that's the stuff I can buy into. The more of this the better, have another go and see what happens again?
 
Drift is caused exclusively by the magnus effect - as opposed to swing which is not. Seam position and surface smoothness matters with swing bowling, with drift and swerve its purely to do with the angle of rotation and the number of revs.

(As a fascinating side note, actually surface smoothness can affect the Reynald's regime in more extremely examples, see for example the reverse magnus effect when a completely smooth flyaway football is hit with sidespin: kick it gently and it will bend one way, kick it harder and and suddenly it bends in the other direction. I'm not aware of any professional sport where this occurs. Perhaps this may account for the unusual results seen at lower velocities on page 33)
I completely agree with that theory and I nearly got done by the effect once. A few years ago while playing GK the striker hit a shot directly into a howling gale, I watched the ball curl as I thought it would and had it covered only to see it stop curling one way and start curling the other! I saved it but looked like an arse to anyone that was watching.
 
Dave! I finally managed to get out to the nets today and i DEFINITELY begun to create drift! It was interesting how i found it. I took five balls down and i'd just bowl them all, go and collect them and repeat etc. I experimented for while with no luck, so i just decided to start practising my different deliveries, so i bowled five leg breaks (no drift) then went and collected them, five sliders (no drift again), Then i bowled five top spinners. Now the very first toppy i bowled DEFINATELY drifted. It completely shocked me. I then just continued to bowl almost complete top spinners (seams maybe 11:30) and noticed the ball drifting quite consistently. These were the things i took note of for you:
1. When i bowled with more side spin, i didn't get any drift. Whether thats because the balls were delivered flatter and thus didn't get as much chance to dip and drift I'm not sure. Thats just the facts.
2. The drift was late, really only occurring when the ball was dipping, which would explain why the toppspinners produced more drift.
3. I pitched them up. To get drift, i really had to toss them up a little so they were landing quite full. too full. I reckon once i get more revs i'll be able to produce drift on a better length ball.
4. Not every single delivery drifted. It may have been because my seam position was poor but i couldn't see the seam anyway.
5. I used an old ball, and the conditions were damp. We had had a bit of rain earlier in the week.

Im so excited hahahaha

Nice job Ben keep it up, its these personal discoveries that energise and keep you going.
I can get drift when I totally relax my arm and the ball feels loose to the point of almost falling out, then bringing the bowling arm through will a real whip (I can hear the whoosh past my ear) but because I concentrate so much on the loose whip effect I seriously lose accuracy, I can drift it with this technique 60-70% of the time in most conditions. I long for the day when I can control it enough to become a stock delivery.
 
Nice work Ben - empirical observations, that's the stuff I can buy into. The more of this the better, have another go and see what happens again?

Hi,

I'm a returning leggie who used to give the ball a big rip (didnt we all ?) and now having got my rip back I'm concentrating on drift. I've been thinking about it and am trying to use my fluid dynamics from uni to understand the airflow over the ball and (probably biased/unrealistic) empircal evidence to explain the drift I sometimes get.

First the physics:

  1. every action has an equal an opposite reaction
  2. the ball in the air exerts a force while rotating on the air, and the air, after being forced to move, imparts a force on the ball
  3. a 'perfect' seam pointing at 45 degrees to first slip would seem counter intuitive to the drift argument bearing in mind the way seamers get their swing.
Now for some details. Please bear with me if you arent used to thinking about micro mechanics of forces (and if my explanation is lacking somewhat...).

If you sit with the ball in your fingers and rotate it at 90 degrees to the wicket (ie if you were to try and get the maximum movement of the pitch) you can imagine the top of the ball moving the air to the left (so imparting a *push* to the right on the ball). Simultaneously the bottom of the ball will be exerting the same amount of force on the air as the top, so countering any drift. This is the case if the ball is moving at a constant height.

However if you think that as the ball starts dropping then the air on the left hand side is exerting more force on the left side of the ball than the right. In my mind this is kind of like the airfoil effect on airplanes. This also matches what we all seem to notice - when the ball drops you get a more movement to the right. When the ball is going upwards you see the opposite effect - the ball drifting to the *left*. I do see this effect when I've given it a big rip and can see a perfect colour presented when using a red/white ball - upwards slight left movement, downwards right movement.

Now consider the effect when the ball is 45 degrees, or seam pointing to first slip. Its more complicated because the angles of the forces are more difficult to reason, but with a pen and paper you can draw the force angles and see it. What happens is that the ball has some top/overspin. You get pressure pulling the ball downwards and forwards - the classic 'dip' we all want - as well as sideways. The added benefit here is that as the ball is 'pulled' downwards it experiences more sideways movement as it moves downwards more rapidly.

So to point (3). My theory which is counter to some, and is also backed by my own experience, is that a scrambled seam is better. Consider the ball with the seam pointing to first slip. In this case the air flow as the ball moves forwards is opposite to the force generated by seam/swing bowling. However with a scrambled seam there is no opposite forces. Finally with a scrambled seam you have more resistance to the airflow because the seam is rotating through the air in a more contrary fashion, thus generating more air resistance. Basically its the same principle as the seam bowler bowling the seam against the wind and generating turbulence.

I have only anecdotal evidence and my own experience to back this up, but if you look at warne he does seem to bowl with the seam scrambled a lot. The advantage here would be the added variation in turn when the ball bounces on the seam or not.

Hope this makes sense!
 
Well Shane Warne recently said that the only thing needed for drift was high revolutions on the ball. That'd make sense as balls without seams can drift if delivered well. I know it's not as simple as that though.
 
Hi,

I'm a returning leggie who used to give the ball a big rip (didnt we all ?) and now having got my rip back I'm concentrating on drift. I've been thinking about it and am trying to use my fluid dynamics from uni to understand the airflow over the ball and (probably biased/unrealistic) empircal evidence to explain the drift I sometimes get.

First the physics:

  1. every action has an equal an opposite reaction
  2. the ball in the air exerts a force while rotating on the air, and the air, after being forced to move, imparts a force on the ball
  3. a 'perfect' seam pointing at 45 degrees to first slip would seem counter intuitive to the drift argument bearing in mind the way seamers get their swing.
Now for some details. Please bear with me if you arent used to thinking about micro mechanics of forces (and if my explanation is lacking somewhat...).


If you sit with the ball in your fingers and rotate it at 90 degrees to the wicket (ie if you were to try and get the maximum movement of the pitch) you can imagine the top of the ball moving the air to the left (so imparting a *push* to the right on the ball). Simultaneously the bottom of the ball will be exerting the same amount of force on the air as the top, so countering any drift. This is the case if the ball is moving at a constant height.

However if you think that as the ball starts dropping then the air on the left hand side is exerting more force on the left side of the ball than the right. In my mind this is kind of like the airfoil effect on airplanes. This also matches what we all seem to notice - when the ball drops you get a more movement to the right. When the ball is going upwards you see the opposite effect - the ball drifting to the *left*. I do see this effect when I've given it a big rip and can see a perfect colour presented when using a red/white ball - upwards slight left movement, downwards right movement.

Now consider the effect when the ball is 45 degrees, or seam pointing to first slip. Its more complicated because the angles of the forces are more difficult to reason, but with a pen and paper you can draw the force angles and see it. What happens is that the ball has some top/overspin. You get pressure pulling the ball downwards and forwards - the classic 'dip' we all want - as well as sideways. The added benefit here is that as the ball is 'pulled' downwards it experiences more sideways movement as it moves downwards more rapidly.

So to point (3). My theory which is counter to some, and is also backed by my own experience, is that a scrambled seam is better. Consider the ball with the seam pointing to first slip. In this case the air flow as the ball moves forwards is opposite to the force generated by seam/swing bowling. However with a scrambled seam there is no opposite forces. Finally with a scrambled seam you have more resistance to the airflow because the seam is rotating through the air in a more contrary fashion, thus generating more air resistance. Basically its the same principle as the seam bowler bowling the seam against the wind and generating turbulence.

I have only anecdotal evidence and my own experience to back this up, but if you look at warne he does seem to bowl with the seam scrambled a lot. The advantage here would be the added variation in turn when the ball bounces on the seam or not.

Hope this makes sense!

More and more people seem to be converting to that way of thinking. Give it a go! A guy on here posted a clip of warne bowling a scrambled seam slider to jaysuriya which evidently drifts. i think you might be right
 
Okay guys this topic has been bugging me a lot recently. All this scientific evidence does make sense but it still doesn't explain everything. If it simply comes down to the amount of revs you put on the ball, then why do finger spinners get more consistent drift than wrist spinners? The more bowling i watch/do the more it seems like the deliveries with a better presented seem get more consistent drift.
 
I reckon it might have to do with the angle finger spinners bowl from compared to wrist spinners. The drift an offspinner gets is in the same direction that the body rotates, which means the drfit will probably be complimented by this angle and thus it looks like more drift is being achieved. On the other hand a wrist spinner creates these same angles, but the drift is in the opposite direction, so it is less pronounced.
 
Hi. I have pretty much mastered the art of drifting the ball, and I have observed and experimented with thousands of drift-related things. My current drift distance (measured with a video, not sure about the accuracy but laterally through the air the ball seems to move that precise amount) is more or less 0.75 meters from around the wickets to a right handed batsman [I'm a chinaman] Here are some of the things I've discovered about drift. For most of these I have scientific (well they must be scientific or I'm bending the laws of physics with my bowling which I assure you I'm not) proof and a lots of past experiences...

1) The more revolutions on the ball, the more the drift (which is obvious)
2) The perfect seam for maximum drift is a 90 sideways degree seam, IF the amount of revolutions is the same as all the other seam positions. The 45 degree seam delivery seems (no pun intended) to drift more because we all naturally put more revs on that type of leg break because the wrist which is the vessel of the finger (that also acts as a "spring") moves partially forwards in the same direction as the arm and finger. (more momentum in the direction of spin - more spin) If you manage to put as much revs on the square leg break it will drift considerably more.
3) The undercutter (flying saucer ball) starts to drift the earliest of all the deliveries and also drifts the second most or possibly most laterally.
4) The more top spin on the ball, the later the drift (that should give you some ideas)
5) The more back spin on the ball, the earlier the drift.
6) I'm not going to discuss the effects if wind on drift since they're obvious and not worth explaining, there are tons of articles that go into the subject.
7) Arm height does affect drift in certain ways, but I have yet to identify them. I'm guessing when I say that a lower release for wrist spinners leads to a bit less drift. (unless you get more revs with a low arm action)
8) Drift starts to happen at about 15 meters travel time, but it all depends on the amount of revs on the ball, type of spin etc. 15 meters is just the distance it starts to drift in my personal experience.
9) Older balls do drift more than newer balls.
10) More flight = more drift
11) The further the ball travels the more it will drift.
12) Bowling with a scrambled seam does not cause the ball to stop drifting, your either hallucinating or putting less revs on the ball than with a conventional seam grip. Ping-pong and tennis balls don't have seams, and they drift BIG!
13) A lot of drift (nearly a meter) does lessen turn considerably because of the angle, but the drift itself is better than an extra bit of turn.
14) Drift can be coupled with swing if you have the right seam alignment, to give you the ultimate backspinning leg break that drifts 0.25 meters and swings an extra 0.25 meters, so it skids on without any turn.

Hope that clarifies a few drift-related matters:) I'll link a video of my bowling soon so you can see a few of these effects for youself. Also: check out Ish Sodhi (a Kiwi leg spinner) I saw him taking a wicket against a West Indie left hander with a ball that drifted an insane amount!
 
Jacques,

You make this sound incredibly easy! I don't know how well resourced you are with regards cameras and places to bowl, but it'd be brilliant to see you doing some of this stuff and for you to try and do this...

Bowl alternate drifting and non drifting balls over a couple of overs with no editing.

Or 3 that drift, 3 that don't, 3 that that do and 3 that don't.

Now there's a challenge!
 
Jacques,

You make this sound incredibly easy! I don't know how well resourced you are with regards cameras and places to bowl, but it'd be brilliant to see you doing some of this stuff and for you to try and do this...

Bowl alternate drifting and non drifting balls over a couple of overs with no editing.

Or 3 that drift, 3 that don't, 3 that that do and 3 that don't.

Now there's a challenge!



Challenge accepted!;) That's too easy:D
Just to clarify: Should I bowl 3 consecutive balls that drift and turn like a normal leg break, then 3 consecutive balls that don't drift at all but still turn? (Each with the same amount of revolutions?) And am I allowed to use any method of my choice? (as long as the ball has side spin)

Does that even count as a "challenge" ? I do that all the time, in nets, games, everywhere. It is quite effective, but only against batsmen that are bothered by drift. (some don't even notice the ball drifting even if it drifts 1 feet or more) My deliveries that drift, drift from middle to outside off from around, and the non-drifters stay straight through the air and turn a bit more. They are similar to Shane Warne's ball to Strauss (although I'll admit mine don't always turn as much)

My only concern is that you might not be able to see the drift because of the angle that I bowl, or the ball will get lost in the background, but I'll make a plan!:) I just wish that you could face me or stand right behind me and watch! That would be much easier than trying to see everything through a video.

Oh and one other thing... You don't have to be well resourced to notice any of those drift effects. I drew a seam on a tennis ball, bowled a top spinner with a millimeter top spin and noticed that it drifted so late it was more akin to very late reverse swing. Doing this with a cricket ball is difficult, but recently I managed to make a cricket ball drift about a bats width in mid air when it was just a meter from the batsman. Only a few times though:( The rest I discovered through experimentation and looking closely at what ping pong, tennis, squash, and cricket balls do when different types of spin are applied to them.
 
I forgot this was here, I should have been posting here all that time! Not sure whether I'm going to continue with this as the more I read the more I'm realising it's far more complex than people think it is, unless of course you want to strip down to basics and just bowl and not worry about why it happens! But for instance this here kind of reinforces my gut reaction to simply putting drift down to the magnus effect, as I believe the Magnus effect has very little to do with the reason the ball swerves to the right in a leg break...

(From http://en.wikipedia.org/wiki/Ball_of_the_Century )...

After a slow run-up of just a few paces, Warne rolled his right arm over and delivered a leg break to the right-handed Gatting. In slow-motion, it can be seen that the ball initially travels straight down the pitch towards the batsman. As it travels towards the batsman, the rapidly spinning cricket ball starts to drift to the right (due to the Magnus effect). [? When viewed from above, if the ball was spinning in a counter-clockwise direction, Magnus effect would have caused it to drift and turn toward left of its path, ie toward wicket; as in the case of a leg break bowler's action.

It would have drifted and turned to right of its path, ie away from wicket, if it was spinning in clockwise direction; as in the case in an off break bowler's action. Magnus effect would not cause a ball would not drift in one direction during flight and then, after pitching, turn in the opposite direction.] The ball ends up bouncing several inches outside Gatting's leg
stump.
 
Dave that's just someone making an unhelpful wikipedia edit which anyone can do. There may be lots of bizarre aerodynamic effects but the straightforward Magnus Effect is well understood and there's no reason why it shouldn't apply to the Gatting Ball!
 
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