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Speed Guns into Context

Manee

Cricketer Of The Year
One thing that I have learnt in my teenage years when it comes to information is that putting things into context is as important, if not more important, than the information itself.

I was just wondering what factors there were which perhaps mean that speed guns are not (or are) perfect judges of speed. As far as I am aware, they measure the release time from the hand and therefore the quickest speed that the bowler produces from the ball. I am also aware that altitude has some part to play in their readings. But, for example, is it possible that a faster bowler may time 135kph whereas a slower one will time 140kph due to other mitigating factors?
 

Dick Rockett

International Vice-Captain
This is a short convo we had on the possible effects. I thought there'd been a whole thread about it but I can't seem to find one.
 

rama_v

Cricket Spectator
Well, if the speed guns they use are the same ones as those that police use to detect speeding vehicles, then I doubt that the speed gun would be inaccurate. These guns use the doppler effect - the change in the frequency of the waves as perceived by an observer who is moving towards or away from the wave source. They essentially fire radio waves at the target, and since the target is moving, when the wave is reflected they should be changed very slightly. The change in frequency between the received signals would be proportional to the speed of the ball and hence the speed of the ball is calculated.Essentially the error in this system is negligable; the only significant errors would be from the user incorrectly ponting the gun obviously not a problem for the speed gun in cricket).

Perhaps if a bird flew in front of the speed gun, then obviously it would be off. Otherwise there should be no reason why there should be inconsistencies or errors. From what I understand, it seems that because its the difference in frequencies between received signals thats calculated, it should not matter what the atmospheric conditions are like. Besides, any atmospheric anomalies are so small as to be negligeable when considering electromagnetic radiation. Sorry for the physics lecture :(
 

Tony

School Boy/Girl Cricketer
The speed on TV I cant see being measured out of the hand as yorkers are always the ones that get the top speed and bouncers although sometimes appearing faster are a slower speed. This may be because digging the ball into the pitch slows it down more but it appears to me due to the trajectory of a shorter ball in part. Also could be because the bouncer has more distance to travel than a yorker.

A bouncer would appear faster probably because a batsmen's eye line although focussed on the bowlers hand is accustomed to the length being about a "good length" and it hitting the pitch at some point, hence losing sight of a beamer (although as said above this may be due a bit to sheer speed of the ball, straight line and not hitting the pitch).

A bouncer also appears faster because you quite often have to do more to play it. A yorker, ie you just have to try to dig it our. A bouncer you need to duck or get onto the back foot and hook or weave etc. Plus movement is more dramatic as the ball is heading for your head.
 

thierry henry

International Coach
I don't profess to know why, but it's palpably obvious that the readings on radars can change dramatically from game to game.

e.g. perhaps in a single ODI series, in game 1 Chris Martin might be averaging 140kph, Kyle Mills 135kph, Shane Bond 145kph. Then in game 2 Chris Martin averages 135kph, Mills 130kph, Bond 140kph. This occurs quite obviously when players move from one series, and one country, to the next. However, it also occurs frequently in the course of two games in the one country in the same series. I'm not sure why, but it's obvious that it's a radar issue and not a case of all of the bowlers simultaneously getting faster or slower.

When putting speeds in context, the most important thing is to only compare players who are playing in the same match, and make comparative judgments.
 

rama_v

Cricket Spectator
I don't profess to know why, but it's palpably obvious that the readings on radars can change dramatically from game to game.

e.g. perhaps in a single ODI series, in game 1 Chris Martin might be averaging 140kph, Kyle Mills 135kph, Shane Bond 145kph. Then in game 2 Chris Martin averages 135kph, Mills 130kph, Bond 140kph. This occurs quite obviously when players move from one series, and one country, to the next. However, it also occurs frequently in the course of two games in the one country in the same series. I'm not sure why, but it's obvious that it's a radar issue and not a case of all of the bowlers simultaneously getting faster or slower.

When putting speeds in context, the most important thing is to only compare players who are playing in the same match, and make comparative judgments.
There should be no reason for the radar to be inaccurate. If it were, then a speeding ticket would never hold up in court. If only that were the case :D
Perhaps the speed guns need calibration and they are calibrated differently? I can't really see a reason why
 

NZTailender

I can't believe I ate the whole thing
Thought this thread might be about good West Coast footballers. Seems I am mistaken.
 

Manee

Cricketer Of The Year
I don't profess to know why, but it's palpably obvious that the readings on radars can change dramatically from game to game.

e.g. perhaps in a single ODI series, in game 1 Chris Martin might be averaging 140kph, Kyle Mills 135kph, Shane Bond 145kph. Then in game 2 Chris Martin averages 135kph, Mills 130kph, Bond 140kph. This occurs quite obviously when players move from one series, and one country, to the next. However, it also occurs frequently in the course of two games in the one country in the same series. I'm not sure why, but it's obvious that it's a radar issue and not a case of all of the bowlers simultaneously getting faster or slower.

When putting speeds in context, the most important thing is to only compare players who are playing in the same match, and make comparative judgments.
I am aware of this and it was a main motive for starting the topic, the question of why there are inconsistencies.
 

Manee

Cricketer Of The Year
There should be no reason for the radar to be inaccurate. If it were, then a speeding ticket would never hold up in court.
Rubbish! Even if speed guns are inconsistent, drivers have to abide by the readings on their speed gauges in their cars which are consistent with the nearby speed guns.
 

silentstriker

The Wheel is Forever
Human beings are a lot less consistent than speed guns. Generally, the speed gun will affect all bowlers equally, so if its overestimating the speed by 5kph, then it'll do it for all bowlers.

I don't see an error where Akthar is times at 120kph and Collingwood at 150kph, unless there was actually something wrong with the speed gun itself.
 

Goughy

Hall of Fame Member
Speed guns are only really useful relative to a certain day and the players involved.

As mentioned above, some days players are slower across the board, other days far quicker.

The thing about speed guns in cricket there is no defined standard or or defined proceedure.

Different places use different types of guns and we have no idea of the positioning of the measuring equipment (that can make a big difference).

We also see many anomalies such as boucers smacking into the keepers gloves measuring 115 kph and the such like.

Cricket speed guns are for fun, they shouldnt be taken as gospel.
 
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skipper

School Boy/Girl Captain
Well, if the speed guns they use are the same ones as those that police use to detect speeding vehicles, then I doubt that the speed gun would be inaccurate. These guns use the doppler effect - the change in the frequency of the waves as perceived by an observer who is moving towards or away from the wave source. They essentially fire radio waves at the target, and since the target is moving, when the wave is reflected they should be changed very slightly. The change in frequency between the received signals would be proportional to the speed of the ball and hence the speed of the ball is calculated.Essentially the error in this system is negligable; the only significant errors would be from the user incorrectly ponting the gun obviously not a problem for the speed gun in cricket).

Perhaps if a bird flew in front of the speed gun, then obviously it would be off. Otherwise there should be no reason why there should be inconsistencies or errors. From what I understand, it seems that because its the difference in frequencies between received signals thats calculated, it should not matter what the atmospheric conditions are like. Besides, any atmospheric anomalies are so small as to be negligeable when considering electromagnetic radiation. Sorry for the physics lecture :(
You don't have to feel sorry. Very good explanation there. :)
 

Arrow

U19 Vice-Captain
They are all measured out of the hand. Once the ball bounces it loses a lot of speed like 20kph or something. I think the radars are somethings optimistic though. In that worlds fastest bowlers comp in the 70s they all struggled to crack 140 and the fastest was 143kph from memory by today many bowlers average in the 140s. Even Johnson bowls close to 150 often.
 

Jono

Virat Kohli (c)
I've always thought that measuring it out of the hand, whilst consistent in the fact that it'll tell us who is the fastest without pitch interference, is a bit useless.

Shouldn't it be more important how fast the batsman faces the ball? How hard the ball is hitting the bat (or batsman)?
 

Manee

Cricketer Of The Year
What is everyone's view on the World's Fastest Bowler competition. Were the camera's facing the batsman end (which meant that Thompson's 148kph ball was actually nearer 170kph) or do you think that the bowlers suffered from attempting to bowl flat out from ball one with no warm up. Remember the incident with Lillee saying that ball three of over two would be his fastest and it turned out to be his slowest of the match.
 

Richard

Cricket Web Staff Member
There's no doubt the technology used in said late-1970s competition produced a different result to modern ones; those measured an average speed across 18 yards, nowadays it's measured all the way down, with the figure given which flashes up after (nearly) every ball being the speed out of the hand.

As already mentioned, speed-guns are not an out-and-out standardised instrument, they're completely down to the TV company covering the game. While there isn't that much variance, because all designs were based on the same specification (the technology used was designed to measure the speed of bullets), there is undoubtedly a little. And there are always anomalies, such as a normal-speed (say, 140kph) ball being measured as 115kph. That will simply be caused by a momental error, and usually such results are excluded and if the producer is quick enough, not even displayed (notice how there are the odd few deliveries here and there where a speed reading doesn't flash up on your screen - that's because the gun hasn't taken an accurate reading, and someone's spotted that it's taken an inaccurate one).

The thing a few older cricket commentators would do well to remember is that the human eye is more faulty than the technology. Provided there's no obvious anomaly, it's laughable to hear people suggest - as older commentators often do - that the reading must be wrong because the delivery looked to the eye a bit faster than it was measured.

Something I would like to see, however, is a single reading (speed out of the hand) changed to a dual reading, featuring speed out of the hand and speed immediately after pitching. Obviously, for a very full ball this doesn't matter (and for a Yorker or Full-Toss there wouldn't even be one) but speed lost - or not lost - off the pitch is vital, almost as important as speed out of the hand.

For example, I've never seen any properly calculated average, but it's obvious from the handful of HawkEye graphics I have seen (probably about 11 or 12 deliveries from each bowler) that Stephen Harmison loses far more speed off the pitch than Andrew Flintoff does. So even though Harmison may propel the ball out of his hand 5mph faster than Flintoff, the reaction-time (which is the most important thing) for the batsman may well be lower for Flintoff than for Harmison.
 

vic_orthdox

Global Moderator
Funnily enough, the one person I know who's faced them both thinks Harmison is much quicker.

Anyways, I don't think speed readings are relevant at all. All that is relevant is how fast the batsman feels that you are bowling, which combines a lot of factors as well as what speed the ball is at one particular moment. Players talk often about how they faced a ball that they thought was particularly quick, or kept to a particularly quick ball, and the speed gun doesn't agree with them. I know what view is more relevant.
 

Richard

Cricket Web Staff Member
Funnily enough, the one person I know who's faced them both thinks Harmison is much quicker.
Oh, he is, there's no doubt about that.

One thing though - when did your friend face them? I presume it was one within a short space of time of the other for starters? And I'm guessing it'd be likely to have been on the 2002\03 or 2006\07 tour?
Anyways, I don't think speed readings are relevant at all. All that is relevant is how fast the batsman feels that you are bowling, which combines a lot of factors as well as what speed the ball is at one particular moment. Players talk often about how they faced a ball that they thought was particularly quick, or kept to a particularly quick ball, and the speed gun doesn't agree with them. I know what view is more relevant.
Well, that's all that's relevant to how the game unfolds, yeah, but speed is about more than that; speed is about thrilling the spectator as well as making one a better bowler. In this context, what it seemed like to the batsman isn't more relevant at all.

As I said, though - reaction-time, not speed out of the hand (which is all the speedgun currently gives out automatically), is the key to how fast a batsman "feels" the ball is bowled. It'd be much more interesting to see this than the simple speed-out-of-hand thing.
 

Manee

Cricketer Of The Year
There's no doubt the technology used in said late-1970s competition produced a different result to modern ones; those measured an average speed across 18 yards,
Is there any proof of this. I have no problem believing that Thomson could not touch 150kph after his back injury.
 

vic_orthdox

Global Moderator
He faced him over in England.

EDIT: and this reaction time doesn't take things into account like bounce, how easy the ball is to pick up out of the bowler's hand, types of action, etc. along with many other factors that designate the speed.
 
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