RaboDirect PRO12 Previews Round 21Ulster Rugby v Leinster Rugby

The opening fixture between Zebre and Ospreys could go a long way to answering some of the questions – a loss for the hosts would put Treviso in the box seat for the Italian spot in next season’s European competition, whilst a loss for the visitors Ospreys, without picking up any league points would take away their mathematical chances of making the Play-Offs .

Bonus point wins are the big prize in the game at Ravenhill on Friday night – a bonus point win for the hosts would secure their place in the Play-Offs regardless of the Ospreys result, whilst a maximum pointer for Leinster would gain them home advantage having already qualified for a top four finish.

Also on Friday Scarlets have the chance to secure European rugby next season needing just two points from their game with Newport Gwent Dragons to deny Cardiff Blues or Edinburgh any mathematical chance of beating them to sixth place.

Glasgow Warriors bonus point victory over Edinburgh in their rearranged fixture last weekend lifted the Warriors into second spot, whilst they have racked up the most wins, 16, in the competition so far this season. Both will stand them in good stead as they will no doubt be looking for maximum points in Italy to support their push for a home Play-Off.  Depending on the results of the May Day game, their hosts Benetton Treviso, will also know exactly what they have to do to claim the Italian berth in Europe next season.

The calculators will be to the fore in Limerick as Munster fans watch their three main competitors for the Play-Offs battle it out on Friday night before Munster take on Edinburgh the following day.  Any points that the Munstermen can take out of this game reduces the pressure on their last fixture, which will be against Ulster.

One of the most exciting penultimate rounds of recent years could set up a grandstand finish for the last round of the regular season.