Although three teams can still capture the title, a win for either Leinster or Munster will clinch it. Should that game end in a draw, however, with neither side picking up a bonus point, then Munster would be declared champions by virtue of a superior points difference of plus 18 to Leinster's plus 14.

For Connacht to snatch the title, they would need not only the help of a draw at Donnybrook, they would also need to beat Ulster by 39 points (including four tries for a bonus point) to overhaul Munster.

Also at issue is who finishes in the top two, which is the likely cut-off point for next season's European Cup. This becomes even more complicated, and depends on how the bonus points pan out. The losers at Donnybrook could finish on anywhere between 14 and 16 points, Ulster still have the potential to reach 14 or 15 points, and Connacht can go as high as 16 points.

Were the losers at Donnybrook to pick up two bonus points for scoring four tries and by losing by less than eight points, then that would put them on 16 points and so out of the reach of both Ulster and Connacht.

Were the Donnybrook losers to pick up no bonus points, however, they could be overtaken by Connacht, just by virtue of the latter winning in Ravenhill.