Fallacy of Net Run Rate (NRR)

Net Run Rate plays a crucial role in cricket. Who has a better run rate always won with more runs. However it is not the case.

Net run rate = (total run scored/total over faced) - (total runs conceded/total over bowled)

Let us assume there are 2 matches between A and B in 20/20

Match1: A 200 (in 20 overs) B 99 (in 20 overs)
Match2: A 99 (in 20 overs) B 100(in 10 overs)

By looking at the result it looks B won with as big margin in 2nd match as A won in the first match. So NRR should be 0 for both A and B

Wait for a minute. Put the formula above
NRR of A = (299/40)-(199/30)=7.475-6.633=0.842
NRR of B = -0.842

Isn't it biased? Let us look at some real life picture. 2009 IPL's last league match Bangalore vs Hyderabad. In that match Hyderabad will be out from the semifinal, if Bangalore wins by 200 runs but will be in if Hyderabad bats first. If Hyd scores 100 and Bangalore is able to make it in 3 overs, still Hyd would have been in the semifinal.

When I look at the formula it looks decent, and seems like it does justice to calculating which team wins by a decent margin. However when I calculate it favors the team which bats first (most of the time).

That is because when a team which bats second does not bat its full quota (if it wins). So in winning cases, its partial over is calculated (100 runs and 10 overs as per example) where as team which bats first its full quota is taken into consideration.

So to make NRR fair to the team batting second, a team should play its full quota or calculate its score using DL.