Getty Images.

Part IV of the series "Rugby Positions by the Numbers" is devoted to the players wearing jersey numbers 9 and 10: the halfbacks, aka the scrumhalf and the flyhalf.

Part I of the series focused on the front row (numbers 1, 2, and 3), Part II on the second row (numbers 4 and 5), and Part III on the back row (numbers 6, 7, and 8). Stay tuned for parts 5 (the centers) and 6 (the wings and fullback).

Spain from 2011, doing what we expect. Getty Images.

In the official HSBC Sevens World Series standings, Spain is currently tied for 17th place with Russia. To put this in perspective, that ranks Spain just below Japan and just above Hong Kong, Zimbabwe, and Papua New Guinea. Wales, on the other hand, is ranked 7th, just below Australia and just above Argentina. You may remember the Welsh team from the 2011 Rugby World Cup semi-finals. You may remember Spain from all those jokes about Generalissimo Franco being dead about 30 years ago.

So when Spain beat Wales 22-7 at the London Sevens on May 12th, 2012, it was kind of a shock. The Spaniards scored within the first minute of play, and before the first four minutes were over, Spain was up 12-0 behind Cesar Sempere's - yes, that Cesar Sempere - seven points. Tom Grabham went into the bin about a minute later, Spain scored another try soon after, and it was 17-0 at the half.

Admittedly, this is the stuff of your standard lightning-strike sevens upset, but, still... Spain? Beating Wales? In London?

Getty Images

Part III of the series "Rugby Positions by the Numbers" focuses on the back row, i.e. the two flankers and the number 8. Read part I on the front row here, and part II on the second row here.

Getty Images

Leinster pulled off a difficult 19-15 road win in Bordeaux April 29th against ASM Clermont Auvergne to advance to the Heineken Cup finals. They'll be defending the Cup against fellow Irish club Ulster, who edged Edinburgh 22-19 at Landsdowne Road the day before.

Leinster cap off a 5-1 Heineken Cup run, with a 34-3 playoff victory against Cardiff as well as a 17-1-3 RaboDirect PRO 12 record, while challenger Ulster had a slightly rougher road, going 4-2 in the Cup, with a 22-16 win against Munster, and a much less impressive 12-9 RaboDirect PRO 12 record. It looks like Leinster will repeat as champions when the two sides meet at Twickenham on May 19.