The fourth day’s play in the third and final Test match between Australia and Sri Lanka being played in Colombo has ended, with the game poised for a fascinating final day that contains all the strategy and tactics that Test cricket aficionados live for. Although the outcome of the rubber has been decided with Sri Lanka winning the first two Tests, each team is highly motivated to win the third, Australia to avoid the humiliation of a clean sweep at the hands of a low-ranked team and risk losing their top-ranked status, and Sri Lanka to enjoy the taste of sweeping the top-ranked Test team. So you could be sure that neither team would be phoning it in.

The match so far has achieved that promise, with fortunes swinging to and fro. Sri Lanka began their first innings with a spectacular batting collapse but recovered later to score 355 runs, a good score in this series. Australian batters seemed to have finally figured out how to deal with spinners and got off to an excellent start, scoring 267 for the loss of just one wicket before a late order collapse saw them all out for 379, a lead of 24 runs. In their second innings, Sri Lanka reached a score of 312 for 8 wickets at the end of the fourth day, a lead of 288 runs.

This is where things get interesting, especially for the Sri Lankan captain who has to make a major decision as to when to declare his team’s innings ended and allow Australia to start their second innings. If he makes the run target too easy, he risks losing. If he makes the target too hard, the Australians may forego any risks and simply dig in and run out the clock and play for a ‘draw’, which is what a no-decision is called in cricket. It is a tricky trade-off.

There will be 90 overs of play on the final day. The Sri Lankan captain needs as many overs as he can to try and get all the Australians out in the second innings in order to win. But he must also not make the run target too easy for them to reach. A target of 289 runs in 90 overs is well within the reach of the top-quality Australian batters, even though it is the final day on a pitch that is slow and increasingly responding to spin, the weakness of their batting so far. So I do not think the Sri Lankan captain will declare his innings closed at the overnight score.

But he cannot allow his remaining batters to bat for too long either because then he has too few overs at his disposal to get the Australians out. Ideally, he would hope that they score about 30 or more runs in ten overs and then declare, leaving Australia a target of around 320 to win in about 80 overs. This is tempting enough for them to try and thus take risks, which is what Sri Lanka wants. The decision may be taken out of his hands if his remaining two batters get out quickly first thing tomorrow morning.

Whatever happens, everything is poised for an exciting final day’s cricket, with only rain the possible spoiler. Fortunately there is no rain in the forecast but from experience I know that the weather in Colombo can be highly unpredictable.