Explained: The line-ball call that sealed Aussie win

It came down to a few millimetres and an agonisingly difficult third umpire call.

It was the closest any team has come to ending Australia's remarkable winning streak, and Meg Lanning's team ultimately notched win No.26 by the narrowest of margins.

While a panicky India made a series of fielding errors in a chaotic final over and Australian pair Beth Mooney and Nicola Carey showed nerves of steel, the match was all but decided by television umpire Phil Gillespie.

The final over began with the Aussies requiring 13 to win, with veteran quick Jhulan Goswami eventually entrusted with the ball following a lengthy deliberation between senior players.

An overthrow and a misfield off the first two balls saw the equation reduced to eight off four.

Goswami then delivered a frightening hand-to-head beamer that clattered into Carey's helmet. The apologetic bowler, whose clearly unintentional mishap might have been caused by a ball made slippery from the dewy Mackay outfield, received a first and final warning from umpire Claire Polosak.

Polosak, incidentally, had started the match as the reserve official but an injury to on-field umpire Bruce Oxenford saw her substituted in for the run chase.

With three runs then needed off the final ball of the match, neither Polosak nor square-leg umpire Eloise Sheridan initially signalled a no-ball when Goswami delivered another full toss that Carey bunted straight to square leg to send India into premature celebrations.

The on-field officials however called for calm as they checked whether the ball was a fair delivery, something they are only able to do when a wicket falls. 

Here's where Gillespie had his judgment tested under intense pressure.

The Marylebone Cricket Club rule he was adjudicating on reads: "Any delivery, which passes or would have passed, without pitching, above waist height of the striker standing upright at the popping crease, is unfair."

It was an indisputably difficult task; Gillespie had to a) make a judgement on where Carey's waist would have been if she had been 'standing upright at the popping crease' and then b) whether the ball would have passed above that point.

Even a trained geometrist would have struggled to make a definitive call.

As former Australia star Lisa Sthalekar pointed out, "Remember the third umpire has to interpret the rule and make a decision in a few minutes.

"Tough one and literally line ball hence why it has split the cricket fraternity."

While Gillespie eventually decided it was a no-ball, there were still two further points of contention.

Given the batters had run a single after the catch was taken, and the ball was subsequently deemed a no-ball, many casual fans would presume the extra run should have counted and Mooney would be on strike needing one to win.

But the on-field officials correctly applied the International Cricket Council's playing conditions.

Those rules state that if a no-ball is called following a check by the third umpire, "the batting side shall benefit from the reversal of the dismissal and the one run for the no-ball" but, crucially, "shall not benefit from any runs that may subsequently have accrued from the delivery had the on-field umpire originally called a no-ball."

Rule 2.6.4 of Appendix D goes on to clarify that the batters must remain at the "same ends as if the striker had been dismissed" even though no runs are to be credited (aside from one penalty run for the no-ball).

So with Carey to face and now two runs required off the final ball (which was to be a free hit), there was still one more matter for the officials; whether Goswami should be permitted to continue bowling.

Australia fast bowler Megan Schutt, watching on from home, tweeted what many fans were thinking; shouldn't Goswami, who has now bowled two over-waist full tosses, be removed from the bowling attack?

Most cricket fans are familiar with that rule but fewer are au fait with a recent update from the MCC Laws Committee in 2018 that now gives umpires more discretion in deciding if full-toss deliveries are dangerous.

Umpires now take into consideration of "the speed, height and direction of the delivery", "the skill of the striker" and "the repeated nature of such deliveries", but disregard any protective equipment being worn by the striker.

If multiple deliveries are deemed dangerous under those updated guidelines, then an umpire can suspend the bowler for the rest of the innings.

Polosak, however, explained to players that Goswami's second no-ball was "away from the body", and therefore not deemed dangerous, meaning she was able to finish the innings.

Carey promptly worked Goswami's final ball onto the leg-side and scampered back for a second run to seal an astonishing get-out-of-jail victory, with Mooney admitting the climax was as confusing on the field as it was for those watching at home.

"I wasn't sure (if it was a no-ball) because of everything that was happening," she said after walking off with an unbeaten 125. 

"But essentially we were just trying to work out whether we got a run for the run that we did, or who was on strike.

"Obviously it was a pretty tight call in the end."

CommBank Series v India

Australia lead India 4-0 on points

Australia squad: Meg Lanning (c), Rachael Haynes (vc), Darcie Brown, Maitlan Brown, Stella Campbell, Nicola Carey, Hannah Darlington, Ashleigh Gardner, Alyssa Healy, Tahlia McGrath, Sophie Molineux, Beth Mooney, Ellyse Perry, Georgia Redmayne, Molly Strano, Annabel Sutherland, Tayla Vlaeminck, Georgia Wareham

India Test and ODI squad: Mithali Raj (c), Harmanpreet Kaur (vc), Smriti Mandhana, Shafali Verma, Punam Raut, Jemimah Rodrigues, Deepti Sharma, Sneh Rana, Yastika Bhatia, Taniya Bhatia (wk), Shikha Pandey, Jhulan Goswami, Meghna Singh, Pooja Vastrakar, Rajeshwari Gayakwad, Poonam Yadav, Richa Ghosh, Ekta Bisht.

India T20I squad: Harmanpreet Kaur (c), Smriti Mandhana (vc), Shafali Verma, Jemimah Rodrigues, Deepti Sharma, Sneh Rana, Yastika Bhatia, Shikha Pandey, Meghna Singh, Pooja Vastrakar, Rajeshwari Gayakwad, Poonam Yadav, Richa Ghosh (wk), Harleen Deol, Arundhati Reddy, Radha Yadav, Renuka Singh.

First ODI:Australia won by nine wickets

Sep 24: Australia won by five wickets

Sep 26: Third ODI, Great Barrier Reef Arena, Mackay

Sep 30 – Oct 3: Test match, Metricon Stadium, Gold Coast (D/N)

Oct 7: First T20, Metricon Stadium, Gold Coast

Oct 9: Second T20, Metricon Stadium, Gold Coast

Oct 10: Third T20, Metricon Stadium, Gold Coast