The Australian driver’s struggles over the Azerbaijan Grand Prix began in qualifying, where he found himself unexpectedly out in Q1 despite seeing a performance gain using a new floor throughout practice. With penalties applied to Lewis Hamilton and Esteban Ocon ahead, Daniel was promoted to P14 on the grid and chose to run the alternate strategy starting on the hard tyre.

This was competitive over the initial phases of the Grand Prix, allowing Daniel to claim a few places on the medium runners ahead. But as can be seen when looking at race pace over the whole field, Daniel’s lap times began to suffer while those around him picked up the pace, so what happened?

Isolating Daniel’s lap times shows that from laps 11 to 25, he suffered a huge three second a lap increase from being in the 1:49s to the 1:52s – forming an exaggerated pattern of lap time increase that was unlike any other driver in the field. This was down to Daniel suffering severe tyre graining, the likes of which he said he had “never” experienced before.

Tyre graining occurs when the tyre is put under stresses that break up the compound, forming small cracks on the surface of the tyre that make it irregular. This irregularity means the driver loses grip, which of course affects performance and lap time.

Pirelli were aware of this phenomenon affecting drivers in the field but from their side felt it hadn’t led to significant performance drops as Pirelli’s Motorsport Director, Mario Isola, said post-race; “A few drivers experienced graining, especially in the first stint, but it did not significantly affect their performance.”

Baku is quite unique in terms of how it treats the tyres with its 2.2km straight and tight, twisty middle sector putting the Pirelli rubber under significant stress around the lap. Due to this, Pirelli increased the minimum tyre pressures for the weekend to 25.5 PSI on the rears and 26.5 PSI on the fronts which reduces the contact patch of the tyres, reducing grip, but ultimately also reducing their susceptibility to stress. Increased tyre pressure itself can result in graining through increasing sliding and increasing tyre temperature – altering the nature of the compound.

The impact of this graining on Ricciardo was an anomaly in the field – while others like Williams driver Franco Colapinto suffered from it too, they swiftly cleared the degradation and their pace recovered. For Daniel, it took almost the entire race distance to clear, with his engineer Pierre Hamlin saying after the fact that his pace towards the end of the grand prix was more aligned with their expectations. By this point though the damage had been done and the team couldn’t recover Daniel’s positions without a safety car, which never came, and he ended the Grand Prix in P13.

VCARB’s investigations into this issue will be made more complicated by the fact that Yuki Tsunoda didn’t complete the full race distance after contact with Lance Stroll ended his race, meaning there’s no real way of the team knowing whether this was a Ricciardo specific or VCARB general problem. But on the more positive side, up to that point of the weekend their upgrades had brought an uptick in performance which they’ll be keen to continue into Singapore.