Aberdeen seem to have simultaneously produced better results against Celtic and The Rangers whilst falling away from their established position as Scotland’s second-best side. What do the numbers say about the Scottish Cup Semi Final?
SPFL Comparison
Here are the comparative numbers from the SPFL season so far:

In the SPFL Celtic have consistently underperformed their actual goals versus Expected Goals. Their shot accuracy matches Aberdeen but Celtic convert 3% less of their shots that the Dons and 8% less of those on target.
Celtic have (an understated) league leading 0.52 goals against in the SPFL. Aberdeen are conceding over 1 goal a game in comparison.
Oddly Aberdeen’s opponents have exactly the same scoring conversion rates as their opponents. Celtic’s opponents have a significantly lower conversion rate that the Hoops.
Celtic v Aberdeen
The tale of the tape in the 4 matches between the pair this season shows the following:

Aberdeen have a healthy Expected Goals (xG) over 1 this season versus the champions. We can expect a Dons goal at Hampden.
Celtic should dominate possession as would be expected but the Dons have managed to take 5.25 shots in the Celts box compared to 8 by the Hoops. Not an overwhelming difference.
In the first meeting of the season, an out of form Celtic won 1-0 against a Dons side who gave it a right good go at Celtic Park. The game was over influenced by referee Madden with the waist high assault on Edouard a low. May played behind Wilson and their attacking approach yielded a season best 38% possession against the Champions, and season high 10 shots, 4 on target. Despite this Sinclair’s cute back heel undid the good work.
Their second meeting was the League Cup Final at Hampden. Another hapless refereeing performance ensued. Dallas looked terrified in the tunnel and awarded Celtic a preposterous penalty which Sinclair missed. Aberdeen’s man for man approach in midfield disrupted Celtic – Shinnie is a massive loss in this regard. That game was marred by a worrying head injury to Mackay-Steven that lulled the game. On that occasion, Christie took advantage of the lull to score just before half time.
The Don’s rarely threatened despite endeavour and sweat.
The December meeting at Pittodrie was the most entertaining with Celtic triumphing in a 7-goal thriller. The Dons persisted with their man to man approach across the park. More refereeing nonsense was observed with Collum awarding a penalty for a Shinnie dive whilst ignoring McGinn’s knee-high tackle on Christie. The Dons scored from all 3 shots on target, 2 of them penalties. Celtic’s xG was below 2 yet scored 4. Not a true reflection of the meetings this season.
Aberdeen will take most optimism from the last meeting in March at Celtic Park against Lennon’s Celtic. A very defensive performance secured a 0-0 in Glasgow. Celtic dominated possession but it was a flat performance. Celtic had Bitton and Brown sitting in whilst Lennon again struggled to correctly configure the forward options Weah, Burke, Edouard and Sinclair.
I’m not here to make predictions and I don’t bet. But I suspect Aberdeen will again go man for man on Celtic. Shinnie is a huge loss as is Logan. Despite his many immature outbursts of emotion in Celtic matches, he is also Aberdeen’s most effective forward passer in these fixtures. Indeed, Aberdeen have relied upon long passes from Considine, McKenna, Logan to attack Celtic. Benkovic and Ajer will be key in that regard. The Dons do not have a creative midfielder to replace Shinnie and Mackay- Steven. Set pieces are therefore key for them. The Dons have had 32 shots versus Celtic this season and 14 have been from corners and set pieces.
With Benkovic winning 6.37 aerial challenges per 90m and Ajer 5.76, they will be crucial in what will be an air borne assault.