It's a rest week in the Six Nations, so I've got a challenge for you: how could a team win the championship despite losing four of their five games? Assume no tied matches

(For those who aren't aficionados, you get four points for a win and zero for a loss, plus potential bonus points: any team can get a bonus point for scoring four tries, and a losing team can get a bonus point for losing narrowly.)

Please spoiler answers đŸ™‚ I'm interested if my way is effectively the only way.

@icecolbeveridge so, if I understand the setup, losing 4 out of 5 means that team has 4 points already.
How many more games are there? And do we know how many points current leader has?
@KarenCampe It's a six-team round-robin (each team plays five games). This scenario can't happen this year owing to the games so far, but it could in a future tournament.
@icecolbeveridge OK in the spirit of @DavidKButler I'm going to #TryMathsLive.
If six teams each play five games, there are 15 games played (6•5/2)
That means there are 60 regular game points available.
If my team lost four games already, but narrowly, they might have 4 bonus points. If they win the fifth game, that's four more points and maybe another bonus point for winning decisively.
@icecolbeveridge #TryMathsLive
Then my team could also have scored a bonus point for having at least four tries in each of the losing matches.
So best case my team that has lost four matches might have eight points on the losing matches & five points on the win for a total of 13.
(Not really sure if all this is correct, because I really don't know much about rugby)

@icecolbeveridge #TryMathsLive
Now let's return to the 60 available points for wins. My team is already taken 4 of them.
That's 56 left, the other five teams have to split those. Average is 11 per team, but you win those sets of 4. How about one team with eight points and four teams with 12 points?

Aha, then if no other team got any bonus points anywhere, my team wins!

@KarenCampe gold star!
@icecolbeveridge not bad, considering my knowledge is lacking in British–centric sports. I did play cricket as a kid in summer camp in the US because they hired many counselors from England.