Bowlers sometimes get warnings for straying onto the "protected area" during Test matches.
But where exactly is this protected area? And what happens if you keep running on it? We reveal all...
What is the protected area?
It's the area of the pitch where bowlers have to keep off - otherwise they may find themselves being taken out of attack by the umpires.
Unlike the crease, the protected area is not marked out on a pitch. It's an imaginary rectangle that runs right through the middle of the wicket.
Why is it protected?
Because it would be unfair for one team to purposely damage the pitch making it more difficult for the other.
A bowler's follow through creates rough patches around the crease which can cause unpredictable bounce and turn.
These areas are often exploited by other bowlers, especially the spinners.
So if a bowler follows through onto the protected area, they will create rough patches on the stumps which would give the batsmen plenty of problems.
How do the players and umpires know where it is?
It's usually marked by two little horizontal lines five feet from the popping crease on either side of the pitch by the groundsman.
This gives the umpire an indication of the area the bowler must avoid when following through.
What happens when a bowler runs onto the protected area?
They are given a warning by the umpire, who will then inform the other umpire standing at square leg, the captain of the fielding side and the two batsmen that the bowler has been cautioned.
What happens if the same bowler keeps running on the protected area in the same innings?
The umpire will issue a second - and last - warning in exactly the same way as the first.
But if the bowler runs onto the protected area for a third time, the umpire will instruct the captain of the fielding side to take the bowler off immediately.
That bowler will then not be allowed to bowl for the rest of that particular innings.
Fielders can also incur the wrath of the umpires too, as Pakistan's Shahid Afridi found out to his cost in 2005.
The all-rounder was banned for a Test and two one-day internationals after scraping his boots on the protected area during the second Test against England in Faisalabad.