Smith started at slip.
Steve Smith's enterprising attempt to catch Sohail Khan at the MCG is legal.
Sohail scooped a Nathan Lyon delivery to fine leg for four, but not before the Australian captain skipped over from slip to leg slip to try to catch him.
It isn't the first time Smith has shown great anticipation in spotting that the ball was going down leg before the batter had played the shot.
Smith caught Pakistan's Fawad Alam down the leg side in a one-dayer in 2014.
Dean Jones said it was technically illegal then.
The laws of the game prevents "unfair movement" of fielders as the ball was bowled.
"We had quite a weird situation where the laws were saying it's illegal, yet the playing conditions said it's okay," Jones said.
The law has since been changed.
The incident sparked a discussion between Jones, Glenn McGrath, and Tim Lane about what field movement is not okay.
Jones said he'd been on the wrong end of "unfair movement" a few times.
He was also given out by a Test umpire who was unaware of the run out rules.
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