Justin Rose has summed up this week's Accenture Match Play Championship in Tucson in a nutshell - and it should make Rory McIlroy, Tiger Woods, Luke Donald and Louis Oosthuizen really nervous.
The first world championship of the season brings together the game's top-64 players, or in this case 64 of the current top 68 with Phil Mickelson and Brandt Snedeker not playing and Ireland's Shane Lowry – McIlroy's first-round opponent today – having dropped to 68th since qualifying by 0.0002 ranking points.
Fifth-seed Rose said as he looked ahead to the most unpredictable week of the golfing year: "If you look at tennis the top-four seeds seem to advance to the semis at every Grand Slam. If the top four advanced to the semis here we'd all be in disbelief. It simply doesn't happen."
The tournament is in its 15th year and the leading four players each time have never made the last 16 without at least one of them crashing out. More than that, there have been only three stagings of the event – and none since 2005 – when all four have made it through their opening matches.
Three years ago England's Ross McGowan, not even in the world's top 1,000 now, put out top seed Steve Stricker, while in 2003 Ernie Els – Open champion then as he is again now – was sent packing by New Zealander Phil Tataurangi. Stand by for the possibility of shocks then.
World No 1 McIlroy, who last month missed the cut in Abu Dhabi in the first week of his mega-money deal with Nike clubs, returns against his former amateur team-mate Lowry. Woods plays his former Presidents Cup partner Charles Howell, Donald faces German Marcel Siem and Oosthuizen tackles Scot Richie Ramsay.
For McIlroy it is a first appearance in America since September's Ryder Cup, where he was part of Europe's fabulous singles fightback. Rose has also not played in the States since Medinah, where he memorably beat Mickelson, but he has added to his match-play record since then.
Two weeks later he was in Turkey for the World Golf Final and took the trophy by beating Hunter Mahan, US Open champion Webb Simpson, Woods and Lee Westwood twice.
However, Ian Poulter is the one who has most excelled at match play. He won this title in 2010, lifted the World Match Play the next season and then gave his inspired display in Chicago.
The first all-Irish encounter is between Graeme McDowell and Padraig Harrington. And while Westwood, Paul Lawrie and Jamie Donaldson are seeded to beat Rafael Cabrera Bello, Scott Piercy and Thorbjorn Olesen, there is a fair chance at least one of them will fail. That is just the way it is this week.