For 18 Test matches, England have forced the 'small margins' that Joe Schmidt is so fond of talking about to go their way.
Eddie Jones' team's performance levels may not be excellent every week, but they win. When they're good, as they were on Saturday, they're outstanding. When they're bad, they still find a way.
Ireland have been reaching a consistent level of intensity that has made them very competitive in the last 12 months, but results have not followed.
They go into the final round of the Six Nations with nothing to play for but a top-half finish for the second season in a row. For a team who came into the tournament with realistic ambitions of winning it and even claiming a Grand Slam, it is a poor outcome.
England come to Dublin on Saturday in search of a world record 19th successive win and back-to-back Grand Slams, the kind of consistency Ireland can only dream of.
Their devastating dismissal of Scotland on Saturday only made Ireland look worse. Schmidt's side have been shown to be tough to beat but beatable while England are invincible.
Under Schmidt, Ireland enjoyed a 74pc win-loss ratio until they exited the World Cup at the hands of Argentina. Since October 2015, they are down to 53pc. During that period, Eddie Jones' men are up at 100pc, while the world champions All Blacks are at 93pc.
Inconsistency was the bane of the 2000s and for all that Ireland are hitting a level of intensity on a weekly basis, their execution under pressure has dropped all too frequently.
While last year's Six Nations can be written off as a transitional campaign, the pattern since is of an inconsistent team.
In South Africa, the series was thrown away but a young squad was given a pass and when New Zealand fell in Chicago to a five-star performance, the trend seemed to be upward all over again.
Two weeks later, they got back to the intensity pitch but lacked the quality to score a try against the All Blacks despite plenty of opportunities in the opposition '22. It's becoming a familiar sight.
The win over Australia meant November was filed in the drawer marked jobs well done, but away defeats to Scotland and Wales have re-opened the discussion about just where this Ireland team are.
A careless performance from the players on Friday night was matched by a poor night in the coaching box.
Schmidt insisted that his team have not gone backwards since the autumn when they scored five tries to beat the All Blacks in Chicago. He also baulked at the suggestion that his side is predictable in attack despite Wales' relative comfort beneath the Millennium Stadium roof. Ireland had seven set-pieces to attack from in the Welsh '22 on Friday night. A return of nine points is at best under-whelming.
Outside the red-zone, their approach play was varied with Johnny Sexton enjoying a fine night when he was on the pitch; but once they got within sight of the line they tightened up.
Schmidt was correct in his assertion that had Robbie Henshaw not had a rush of blood to the head when trying to help Rory Best over the line, they could have won the game, but for all that he railed against the circumstances beyond his team's control he must look at himself in this week's review.
Why, for instance, did Conor Murray remain on for 15 minutes while playing with one arm?
Why was Tommy Bowe on the bench if he wasn't worth bringing on until the game was over? Why did he take CJ Stander off?
Wales scored 10 points while Murray was injured, while their total while Sexton was off for around 18 minutes between his HIA and his sin-binning was 15 points.
Schmidt had his full deck to choose from, but the highest quality players he could pick couldn't unlock a stubborn Welsh defence that had leaked five tries in three games before Ireland's arrival in Cardiff.
The make-up of the back-row, where dynamism trumps balance, needs to be reviewed in the coming week with Jamie Heaslip now under pressure to retain his place. Best's form must also be called into question.
There were a few examples of Ireland's inability to execute but one stands out.
In the 52nd minute, when Ireland were dominating possession, they worked the ball cleverly through five passes to Best in midfield. Simon Zebo's pass was slightly off, causing the hooker to check his run, but Henshaw, Heaslip and Keith Earls were outside him where they have a three-on-two in space; the kind of opportunity they dream of.
Best opted to tuck the ball under one arm and straightened. If New Zealand's Dane Cole was in a similar situation, the pass would have been delivered without hesitation.
If Ireland need to progress, all of the players must trust their skills regardless of the number on their backs.
Schmidt pointed out that the statistics showed that it was an even match and Rob Howley scoffed at the notion that the men in green were predictable, but there must be a reason why Wales were able to score three tries and Ireland couldn't get over the line with the same amount of ball, territory and line-breaks.
"It's frustrating at times, we're trying to get to the width a lot and we did that a lot in areas of first phase and there's opportunities there for us," Henshaw said.
"A few handling errors let us down, particularly one in the first half when we got a turnover in defence and if we had gotten it wide there was acres of space in the left corner. Little things like that let us down.
"There's areas we need to clean up in our game and in our attack we need to work harder to get back into shape. Especially in the backs, myself included, we need to work harder to get our shape and work the forwards."
In defence, Ireland were once again caught narrow. It didn't cost them tries directly, but it allowed Wales to grow their confidence in that first half.
Ireland knew Rob Howley's men are most dangerous off set-piece ball, but still it was from a lineout that the home side worked their first and second tries.
After shutting out France it was a disappointment to see them concede three tries against top-class opposition.
With their attacking issues, insistence that kickable penalties must go to the corner and inability to cross the whitewash against the better teams, Andy Farrell's leaky defence is a major issue.
On Saturday, the most consistent team in European rugby arrive into town for a celebration.
A one-off win can send the fans home temporarily happy, but this team were supposed to have moved past that point. Increasingly, it looks like they haven't.