|Australia v England, Third Ashes Test|
|Date: December 14-18 Time: 02 : 30 GMT Place: The Waca, Perth|
|Coverage: Ball-by-ball Test Match Special comment on BBC Radio 5 live sports extra, Radio 4 LW and the BBC Sport website. Live text comments on the website and the BBC Sport app. Full coverage details|
Pace. Expect it to be on the agenda again during this week's third ashes trial.
The pink ball and the reflectors gave Adelaide the movement of Edgbaston during the periods of the second test, and England took advantage.
But tourists can not always expect that kind of help during the remaining matches.
This week in Perth, the difference in the speed of the two attacks is set again to reach the fore.
Why does Australia have bowlers faster than England? Are there flaws in the English system that prevent bowlers from reaching excessive speeds? And why is it important?
85.6mph or 89.1mph: what's the problem?
For mere mortals, the difference in speeds we are discussing seems insignificant.
If Chris Woakes, the fastest bowler in England, averages 85.6mph and Mitchell Starc, the fastest in Australia, has 89.1mph, what's the problem?
On top of that, there's an argument that you do not have to be playing at the speed of light to be successful in Australia.
Glenn McGrath, who has taken more test terrains in Australia than any other sealant, did so by favoring accuracy over speed for most of his career.
But the devil is in the details.
Just below McGrath on the list are Dennis Lillee, Craig McDermott, Brett Lee, Mitchell Johnson and Jeff Thomson. Everything, with the exception of McDermott, had a rhythm to burn.
As the following chart shows, Australia has sent many deliveries over 87 mph during the current series. Those deliveries have produced 21 plots of land, compared to four in England.
When the launch is flat and the ball does not move, the extra four or five miles per hour can make the difference: more Probably beat the batter by pace, magnify any flaw in the technique or test your courage.
This illustration below shows how fast the deliveries of different speeds arrive at the batter, highlighting the difference of time in playing a ball in excess of 90 mph, or a low in the 70 or 60.
"The main difference is knowing that there is a different length that bowlers of 90 mph or more can play," said former England hitter Nick Compton.
"In the county cricket, or international cricket you play in England, bowlers prepare it, yes, there may be some gorilla, but it's not that fast, it will not really rush you."
"When someone starts to reach those steps that exceed 90 mph, you think, wait a minute, there may be a couple of shorter balls and I have to be prepared for that." Then, suddenly, they become fuller and your feet do not move.
"There is also the aspect of fear, if someone is really fast and hostile, whether he has practiced it a million times or not, it's not pleasant, it's something he can work on, but until know what it is you like to face that kind of hostility, there is not much you can do to prepare for it. "
* The speed of the ball of the hand is the only measure used, with other factors such as the environment not considered.
Was the rhythm born or was it made?
If the impression is that Australia is blessed with dozens of fast bowlers, lurking around the inside ready to break the English batting, that's not entirely accurate.
In addition to Starc, Pat Cummins and Josh Hazlewood, Nathan Coulter-Nile and the injured James Pattinson are able to throw at great speed, but not all states have two or three players of 90 mph.
"They do not fall off the trees," said former Australian boulder, Chris Rogers. "Right now we're a little blessed to have three rapids on the test side that are starting to peak at the right time."
But athletes are a product of their environment.
The skills that have brought James Anderson and Stuart Broad to more than 900 test terrains among them were learned mainly in the English conditions that help the ball move. In Australia, a bowler may have no choice but to win 90 mph or more if he wants to reach the top.
"Australians are accustomed to happy terrain," said England bowler Toby Roland-Jones. "They harvest much less, so the passage through the air has a high value."
McGrath believes that really fast bowlers are born, instead of being manufactured. David Saker, the former England bowler who now works with Australia, suggested that the weather and the outdoor lifestyle could make it more likely that Australians will discover sprinters.
There is also the belief that the additional passage yard, the four or five miles per hour that makes the difference, can not be trained.
"I do not think if I tried harder or if I ran harder, I would find a way to go 85 mph," Roland-Jones said.
"I get to 83 mph, that can change day by day and I'm not at my limit.
" You can find a way out of a couple of miles per hour of different players bowling, but finding that extra five miles per hour towards that 90 mph mark, where it seems to make a difference, is really complicated. "
But there is disagreement: both Steffan Jones, a former bowler from Derbyshire and Somerset, and Ian Pont, a former bowling coach from Bangladesh, believe that an extra rhythm can be taught.
"It's about having the right understanding of bowling action and training correctly," said Jones, now a coach with a self-confused rhythm obsession.
"I'm not saying no one can be teach how to do it, but if someone has the raw materials to sheathe at a decent pace, one or two additional meters could be added. if you study his action and then do the right job. "
Pont, who had spells with Nottingh amshire and Essex, added:" From a position of human movement, can we run faster, jump higher or throw further away? The answer to all the questions is yes, then, why should fast boluses challenge the biomechanical trend?
"Unless you have the most efficient bowling action on the planet, you can improve it, I can not name you a bowler on this planet that has reached its maximum speed."
** It is assumed that all deliveries have a good duration, and the average speed during the first two tests has been used for each bowler.
Did England slow down?
Even if England does not have bowlers capable of matching Starc or Cummins, 90-mph bowlers do exist in county cricket. they just are not in the Ashes squadron.
Liam Plunkett was not selected, Mark Wood was not in shape, Tymal Mills only plays cricket T20 and Jamie Overton was injured. George Garton of Sussex is young and raw, and, going back further, Stuart Meaker and Mark Footitt have eluded the team without having played on the test side.
Maybe the question is not why England does not have a fast bowler, but why are not they on the team?
The finger often points to the structure of the county cricket.
The greenest courses at the beginning and end of the season mean that the 80-mph bowler can teeter the ball successfully, while a load of 14 first-class matches plus one day and one T20 cricket (more matches than the Australian national season) is demanding for the body.
"It's hard for men to maintain that fitness throughout the season," said Roland-Jones, who missed the Ashes tour with a stress fracture in his back. .
"Any bowler who plays bowling in all three formats is certainly very complicated and can lead to an element of trying to control their feelings, their physical condition and try to make sure that it can be effective in a long period of time. "
The England and Wales Cricket Board (BCE) has tried to change the courts in the County Championship by introducing new rules on the pitch: visiting teams now have the option to play first if they wish.
The theory is that the sides of the house have to produce flatter surfaces, which means that unprocessed rhythm and spin are more valuable weapons.
In the case of Somerset, his home in Taunton helped left-handed pitcher Jack Leach to become the leader of wicket-taker in Division One over the past two seasons.
"The new launch rules have helped," said Rogers, a former Somerset captain. "A pitch like Somerset will also develop fast bowlers – you can not be a mid-range bowler because there's nothing there for you."
All this is an inaccurate science. How many times have we heard an old bowler sing that the modern race does not really know enough, that they spend too much time in the gym, instead of being in shape bowling?
You may have a point, however. "Many men get muscular, but muscles can make you strong but slow," said Pont. "You do not have to be strong to hit fast." Dale Steyn and Brett Lee, for example, are not muscular types.
"Strength and conditioning are a myth, even if it's done for the right reasons. . I bet Ian Botham did not see the inside of a gym during his career. "
Going deeper, Jones suggested that competitive cricket at too young an age can discourage youngsters from bowling quickly.
Are parents, coaches and perhaps even the players themselves happy about slower bowling if that means precision, control and victory, rather than risk?
"Instead of asking a young player if he has won, or what his numbers are, I want to know how fast he has played," Jones said.
Kevin Shine, the ECB's fast bowling principal coach, is used to criticizing the English system, but says nothing will be used as an excuse.
"We are not arrogant enough to think we know everything," he said. "We constantly seek to improve the use of information about performance, injuries and workloads.
" You must not lose sight of the fact that fast bowling is absolutely brutal and our boys do a lot. "
Is the future of England fast?
England's highly qualified medium and fast bowlers have been incredibly effective in their own conditions: only once since 2012 England lost a series of Tests at home.
But there are two problems. Anderson, 35, and Broad, 31, are closer to the end of their careers than the start and, recently, England have not been able to win away from home.
His only triumph in the distance since 2012 was in South Africa, where the movement of the ball may be similar to that of England. When the situation has demanded pace, or maybe turn, England has failed.
England could expect Wood to overcome his injury problems in order to significantly increase his 10 test casings.
Much thought is given to Jamie Overton, but a problem in the back restricted him to only six first class matches in 2017. Garton was summoned to the England team as coverage at the start of the Ashes tour, but he accepted 86 of 10 overs when he played for the Lions in November.
"Jamie Overton: at full speed, he is someone who not only pulls fast, but has the skills to do it, that always adds that extra advantage to someone who can accelerate the pace," Roland said. Jones.
"There is a lot of talk about George Garton, who certainly has a bit more action, when he clicks for it, he can really increase his speed there.
" England has focused on producing them , and they're doing it, but they're trying to find these guys in the game and keep them in shape. "
Beyond the names that have been presented as prospects for England, Shine has identified much more rhythm .
"We have Tom Barber, a young left-winger from Middlesex, the fastest bowler we've tracked in our Lougborough tests, he appeared at 94 mph on the television speed gun.
"Zak Chappell of Leicestershire is 6 feet 5 inches and Ollie Stone, coming back from injury, has a regular clock at 90 mph. George Scrimshaw is another very tall bowler and Josh Tongue is with the Lions this winter.
"They're out, we're not fighting for high-speed bowlers, but it's not just about rhythm.
" We want them to be coherent, robust and skilled. "
There you have it, the closet is not empty, the challenge is to keep the bowlers in shape, give them a domestic game that prepares them for international cricket and is lucky that they will eventually reach the sand test