London:West Indies are confident of chasing nearly any total in this event; Sri Lanka believe there is no score they can't defend. Clearly, something will have to give in their World Twenty20 semi-final.
Friday's match at the Oval sees two exciting sides up against one another and, while Sri Lanka will start favourites, the West Indies have shown that they are not to under-estimated.
Sri Lanka, who have an admirably well balanced side for cricket's shortest format, have yet to lose a match at this tournament.
In Sanath Jayasuriya, the man for whom the phrase 'explosive opener' might have been created, and the inventive Tillekaratne Dilshan, who every time he plays the 'Dilscoop' delights spectators and infuriates opponents in equal measure, they have a first-wicket partnership that can score rapidly.
Behind them come the likes of captain and wicket-keeper Kumar Sangakkara and Mahela Jayawardene, a pair of class batsmen.
But it is their bowling attack which has really proved a problem for most of their opponents at this tournament.
For years now batsmen around the world have found that scoring quickly against off-spinner Muttiah Muralitharan is easier said than done.
But he has now been joined by Ajantha Mendis, a spinner who flicks the ball out of his fingers in a way not seen in international cricket since Australia's John Gleeson in the early 1970s and whose 'carrom ball' has left countless batsmen bemused.
"Murali can turn the ball on any surface," Jayawardene said of the star off-spinner, who is the world's highest wicket-taker in both Tests and one-day cricket. "And if Ajantha sticks to his plans, we have a fairly good chance of going all the way."
That bowlers are restricted to four overs each in this tournament works in Mendis's favour in that by the time batsmen have evolved some sort of plan to combat him, his spell is over.
He took three for nine against New Zealand at Trent Bridge on Tuesday in a match Sri Lanka won by 48 runs to secure their last four spot.
"Ajantha was brilliant," said Sangakkara. "He is very difficult to read and he has an attacking mindset. It's a great ability to have."
But it was at the Oval, a happy hunting ground for West Indies down the decades, that the men from the Caribbean beat Australia by seven wickets in their tournament opener.
That victory owed much to a quite brilliant 88 from West Indies captain Chris Gayle, the left-handed opener striking some of the biggest sixes ever seen at the south London venue.
Gayle has yet to hit such heights again at this competition but the knowledge of what he can do is enough to make most opponents pause for thought, although Sri Lanka's unorthodox Lasith Malinga is unlikely to be as easy to 'tee off' against on a bouncy pitch as was Australia fast bowler Brett Lee.
In the likes of Shivnarine Chanderpaul and Ramnaresh Sarwan, West Indies have batsmen capable of plugging the gap if Gayle fails, while Dwayne Bravo is a talented all-rounder and the leader in the field of a team capable of taking some spectacular catches.
No wonder Gayle said after his side's five-wicket Super Eights win over England at the Oval, a victory which took them into the last four: "To be honest with you, a lot of teams fear us.
"We were written off from the start of the tournament and we are actually in the semi-final. If you look at each and every one of our players, we are actually winners."
Sri Lanka (probable): Tillekaratne Dilshan, Sanath Jayasuriya, Chamara Silva, Kumar Sangakkara (capt/wkt), Mahela Jayawardene, Jehan Mubarak, Angelo Mathews, Lasith Malinga, Muttiah Muralitharan, Isuru Udana, Ajantha Mendis
West Indies (probable): Chris Gayle (capt), Andre Fletcher, Lendl Simmons, Dwayne Bravo, Kieron Pollard, Shivnarine Chanderpaul, Ramnaresh Sarwan, Denesh Ramdin (wkt), Jerome Taylor, Sulieman Benn, Fidel Edwards
Umpires: Aleem Dar (PAK) and Rudi Koertzen (RSA)
TV umpire: Daryl Harper (AUS)
Match referee: Alan Hurst (AUS)