Bangladesh must beat Afghanistan by at least 41 runs if they bat first, or chase down the target within a specified number of overs if they bowl first, on Wednesday if they are to reach the final of the tri-nation ODI series taking place in Abu Dhabi.

The equation became clearer after Afghanistan crushed Zimbabwe by 158 runs in the second match of the series on Monday.

Afghanistan and Zimbabwe now have two points each, while Bangladesh are yet to earn a point, having lost their opening fixture against Zimbabwe by 99 runs.

If Bangladesh bat first, they must win by at least 41 runs to surpass Zimbabwe's net run rate and qualify for the final.

If Afghanistan bat first, Bangladesh's required chase rate will depend on the target. They must complete the chase within 40.3 overs for a target of 200, 41.3 overs for 250, and 42.2 overs for 300.

The equations differ if Bangladesh level the scores with a boundary.

For a target of 200, if they level the scores with a four, they would have to win by 41.1 overs. If they level the scores with a six, the would have to finish the chase by 41.4 overs.

For 250, the corresponding deadlines are 42.1 and 42.3 overs.

And if Afghanistan set a target of 300, Bangladesh must complete the chase by 42.5 overs after levelling the scores with a four, or by 43.2 overs after a six.

A win that fails to meet the required margin or net run-rate threshold would leave Bangladesh out of the final, allowing Afghanistan and Zimbabwe to advance.

Zimbabwe can qualify alongside Afghanistan if Bangladesh win by 39 runs or fewer. Bangladesh, meanwhile, would join Zimbabwe in the final if they defeat Afghanistan by 218 runs or more, eliminating the Afghans.

Bangladesh have no one but themselves to blame for getting entangled in such permutations and combinations, after a batting collapse on Saturday handed them a crushing defeat against Zimbabwe while chasing 277.