In the 12 minutes after halftime when England blew the contest asunder, they launched Clarke like a javelin at the heart of the Welsh defence five times in quick succession.
Look closer, and the picture becomes more revealing. Clarke's four touches in the first half came from two back-row moves at a scrum, a line-out, and an inside pass from Rob Andrew. Close-quarter trade. At the start of the second half, he popped up three times in the threequarter line in 10 minutes. Wales' backs were faced with 6ft 5in and 17st of Clarke on the rampage. As England's ambition expanded, so did Clarke's.
The back-row is, almost literally, England's greatest area of strength. It has been their focal point - and their rallying point - all season. And it is as efficient a barometer of the team's mood as it is a unit an the pitch. When Clarke, Tim Rodber and Dean Richards are thundering, so are England.
The progression from limited outlook to limitless horizon that has been England's transformation this season has been characterised by two things: Richards at the heart of devastating mauls, and Rodber and Clarke leading the charge over the gain line.
Cardiff was slightly different. Not for Richards, who was inevitably peerless in his closeted element. His socks stayed close to his knees just long enough to get the first verse of the anthems out of the way, and then it was business as usual. Naturally, he directed the flow of the maul which led to Victor Ubogu's try.
He forced countless turn-overs, once spinning two Welsh forwards over his hip to present Kyran Bracken with perfect ball. His positional sense was flawless. The only time that Neil Jenkins missed touch all day, the ball arrowed directly at the biggest chest on show. It was not until the 55th minute that Richards was seen making clear ground with the ball in his hands, but his influence had long since been decisive.
But where Ireland and France had been subjugated by an endless series of percussive runs, here Clarke and Rodber made a grand total of 10 breaks between them. Rodber, such a high-profile dynamo in Dublin and at Twickenham, was enlisted to more mundane duties of the grappling variety, while Clarke frequently had to abandon his optimistic position of standing off a maul waiting for the ball, to dive in and help hunt for it.
This is a compliment to the Welsh, of course, but for England it will form one of the areas their manager, Jack Rowell, said they would be working to improve.
But - and this is the real point - three of the flankers' 10 breaks resulted in England's three tries. Another brought a penalty which Andrew converted. It is not just that England break free when the back row does, but they cannot unless it does. And the lesson of Cardiff is that England have not yet quite worked out a consistent way of making that happen.Reuse content