Before he was disqualified, Mercedes driver George Russell was hailed for committing himself to an aggressive and ambitious on-stop strategy at last Sunday's Spa F1 round. F1Technical's senior writer Balazs Szabo delivers his tyre analysis from the Belgian Grand Prix.

The final result of one of the best races of the past few years wasn’t decided until well after the chequered flag had been waved. On track, it ended with a Mercedes one-two, George Russell ahead of Lewis Hamilton, the pair joined on the podium by Oscar Piastri.

However, post-race scrutineering revealed that the number 63 car was underweight as per the technical regulations and therefore George Russell was disqualified, the win going to his team-mate Hamilton, with Piastri now second and Charles Leclerc moving up to the third step of the podium.

Pirelli's Motorsport Director Mario Isola noted: “First of all, let me say this was a really exciting race. It’s been quite a while since Formula 1 has put on such a show.

"It’s unusual to see a race where the outcome is so uncertain, with the top three within just over a second of one another and the first six finishers, all of whom could legitimately claim to have aimed for the win or at least the podium, all finishing within under 10 seconds. It’s a shame the race result had to be changed but, as even Mercedes agreed, the rule regarding weight is very clear.

Strategy gamble

On the grid, the vast majority of drivers had opted to start on the Medium. The only exceptions were Sainz and Zhou who chose the Hard and Ricciardo who preferred the Soft.

The two-stop was the most popular strategy, while the Hard was the compound that performed best, both in terms of degradation and performance.

Zhou was the only driver to retire and of the remaining 19, five of them – in their finishing order –Russell, Alonso, Stroll, Magnussen and Tsunoda, only pitted once, going from the Medium to the Hard, with the first two of these finishing in the points places, respectively first and ninth.

Before he was disqualified, Russell pulled of a strategic masterstroke gambling on a one-stop strategy to win the Spa round. However, the Briton revealed that he was not always convinced that the single-stop strategy would work out.

After the second pit stop of his direct rivals Lewis Hamilton, Charles Leclerc and Oscar Piastri, he was constantly monitoring their pace to figure out how much of an advantage the fresh set of hards would provide them.

"And they just weren't catching me as quick as I expected. And my lap times were just improving every single lap. And that was far from what we all anticipated. But it just goes to show how difficult it is to predict. I think every lap we were driving, 20 drivers, full gas around this circuit and it was just getting faster and faster," said Russell.

Piastri, who flew during his last stint, revealed that he never seriously deemed the one-stop strategy viable, saying: "It did cross my mind, but not seriously enough.

"I was amazed at how much difference the dirty air made. I think when Lewis and Charles pitted for the second stop, I think I went like one second faster just because I had clean air. So that was impressive, but then it felt like it kind of degged a little bit again after that point.

"And with 16 laps, I think it was, or 15 laps around Spa, it felt like a pretty big risk to try and go to the end. And I knew that even with the tyre advantage that we were building up, that we had a strong chance to try and win the race anyway that way.

"So yeah, maybe we should have considered the one-stop a little bit more. But I think with the two-stop, I think we did a good job of capitalising on it. Just unfortunately, on my side, didn't give us the track position in qualifying."

The prize for the longest stint goes to Russell who did 34 laps on the Hard, while on his final stint, Hulkenberg went the furthest (24 laps) on the Medium.

Although the Friday practice sessions indicated that the two-stop strategy would become the quickest approach to complete the 44-lap Belgian Grand Prix, there were a series of factors that made the single-stop strategy possible.

"Going into the race, we stated that a one-stop was not fast enough compared to a two-stop, but leaving aside Russell’s disqualification, his performance would disprove that theory. For a preliminary explanation, at least in terms of tyre behaviour, there are some factors that stand out.

"First of all, today’s track temperature was around 10 degrees higher than during FP2 and that probably contributed to very limited graining on the Hard, which on the other hand was very significant on the Mediums on a long stint.

"Furthermore, we can assume that the teams worked hard on defining car set-up to find the best compromise between a wet qualifying and a dry race and to try and protect the front axle, which was most prone to graining. A third element to consider is that many drivers made a point of looking after their Mediums very carefully, especially in the quickest corners.

"Two thirds of the race was a fascinating chess game, with moves and countermoves, especially among the leaders, but also further down the field and then it all came to life over the final 15 laps or so, with all the drivers beginning to push and fight for track position. It was a show that, as I said earlier, means we go into the summer break with a strong desire to see something similar in a few weeks’ times in Zandvoort and indeed for the rest of the season.”