Not a lot might knock Steven Smith out of his batting stride at The Oval as he compiled his thirty first Test century though David Warner's uncommon guard almost did it.

A section for Channel Seven by Ricky Ponting through the lunch interval on the second day introduced consideration to the crater Warner had created within the batting crease as a part of a plan to assist his footwork.

Unlike a standard batting guard the place the marks run perpendicular to whichever stump the batter asks for, Warner dug what resembled a small trench parallel to the stumps with holes at both finish.

Smith, who got here in following Warner's dismissal shortly earlier than lunch on the opening day, admitted it had taken him abruptly.

"I nearly fell in it," he joked. "I got used to it eventually but almost twisted my ankle a few balls to be honest then I sort of got used to it. I've never experienced that before on that side really, you occasionally get the edging of the footmarks at the backend of the game where you kind of fall into them where you are off balance, but when I'm moving to off stump and I've got this hole there it's something I haven't experienced before.

"I'd no thought it was coming till I walked out and marked my guard and noticed this huge gap. Was simply questioning who made this? Think I requested Marnus [Labuschagne] what was occurring on the finish, there is a huge gap I'm about to fall into. It was odd."

"Maybe he ought to it extra usually, it labored for me," he said. "He can maintain digging that gap I suppose… regardless of the batter wants I suppose to get themselves into a great place."

David Warner made 43 after employing a new method of marking his guard•Associated Press

Warner, whose position has been under scrutiny, had made a compact 43 on the opening day, becoming increasingly assured after a tricky first hour, and later said it was as good as he had felt for 24 months.

Ponting, who is Warner's coach at Delhi Capitals in the IPL, explained that the method he was using was to aid his footwork and stop him going too far to leg stump.

"He's really obtained a line going throughout the again vertical to the stump line," Ponting said. "And take a look at every finish of that line there, there's two fairly deep holes. Now I do know for a reality, having labored with David Warner for the final couple of years, lots on his batting, when he is batting his worst, his set off motion has gone again outdoors leg stump.

"So only two days ago he came up with this plan of digging two holes and making sure that when he moved his foot that his foot stayed within those two holes. If he moved back and across, he could feel his heel going into the hole. If you move too far across to the off stump, then his toes go into the hole.

"That's the signal of a contemporary participant, somebody that is performed over 100 Tests nonetheless looking for a approach to get higher."

Although what Warner did was unusual, it did not contravene any Laws which only come into play for the protected area in front of the popping crease where bowlers are not allowed to encroach in to and batters are not allowed to enter "with out cheap trigger" or take their guard in.

Andrew McGlashan is a deputy editor at ESPNcricinfo