SRR = Average run rate over the tournament while scoring
CRR = Average run rate conceded over the tournament while bowling
NRR = SRR - CRR
Prior to this match, New Zealand:
Scored 1488 runs in 294* overs (SRR = 5.06)
Conceded 1563 runs in 348* overs (CRR = 4.49)
Their NRR = 5.06 - 4.49 = 0.57
Prior to their match, Pakistan:
Scored 1710 runs in 339* overs (SRR = 5.04)
Conceded 1772** runs in 303.7* overs (CRR = 5.83)
Their NRR = 5.04 - 5.83 = - 0.79
*if you're bowled out in less than 50 overs, run rate is calculated over all 50 overs
** Adjusted for the 301 target India set through DLS
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So lets say NZ get bowled out for 180 today. Their final NRR will be 4.84 - 4.69 = 0.15
In the next game, if Pak go first and score 350 (taking their SRR to 5.29), to match NZ's NRR of 0.15 they need a CRR of 5.14.
Say Bangladesh score x runs, then (1772+x)/353.7 = 5.14, then x is 46 runs.
If Bangladesh go first and are 100 all out (taking Pak's CRR to 5.29), then Pak need to chase it down in say x overs to get a SRR of 5.44.
(1810)/(339+x) = 5.44, then x is -7 overs.
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Basically, as long as Bangladesh score more than 50 runs in either innings, Pakistan are out of the tournament.