The Carolina Panthers and New Orleans Saints are both 9-3 and tied for the lead in the NFC South, with four games left to play, two of which are against each other. So who wins the division if the Panthers and Saints split their games against each other and win the remaining games? The Saints. You can find the NFL tie-breaking procedures here. In that scenario, the two teams would both be 1-1 against each other, 5-1 in the NFC South, and 10-4 in common games. The Saints though would have the better conference record at 10-2 (losses: Carolina and Seattle) while the Panthers would be 9-3 (a loss to the Saints plus Seattle and Arizona). Not all losses are equal in the NFL — if you’re going to lose, lose against teams in the other conference. Two of the Saints’ losses are against teams in the AFC (New England, NY Jets) while the Panthers have only lost to one AFC team to date this season (Buffalo).
So unfortunately the Panthers may well have to sweep the Saints to win the division.