MONDAY MORNING DEBRIEF: Why Ferrari's set-up and strategy gamble to win in Monza didn't pay off

The SF-23 which had been so uncompetitive around Zandvoort’s long corners last week was in its element at Monza. Its two key strengths are good straight-line speed and very driveable slow-corner balance. Perfect for Monza. But Ferrari decided to capitalise further on those basic strengths by using an especially low-downforce rear wing – actually the same wing it used here last year.

Running minimal rear wing is probably optimal for single-lap pace around Monza, though it invariably brings with it a tyre wear penalty over the bigger wings chosen by most of the others. Red Bull, very confident of the RB19’s underlying pace and chasing a championship – and the consecutive win record along the way – optimised their car for race day with a significantly bigger rear wing than Ferrari.

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That brought with it a small lap time penalty in qualifying, and in combination with Ferrari’s qualifying-favouring choice, brought the two cars extremely close together on Saturday, enough for Carlos Sainz to take pole by 0.013s from Verstappen.

There was a strategic complication associated with the skinny wing, however. The fastest way to run the race is invariably with a one-stop strategy, because the pit lane loss is unusually big at around 25s, and the tyre degradation – the amount of performance the tyre loses with mileage – is low. But you can only pull off the one-stop strategy if your tyre wear allows you to.

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Tyre degradation might be low, but tyre wear – how much tread is used – can be uncomfortably high, especially if you are running light on downforce. Degradation and wear are completely different tyre limitations. Depending upon the particular demands of a circuit, you can have very little performance loss right up until the time you run out of tread. Alternatively, you can have massive performance loss but still lots of tread left.

Around Monza, it’s inevitably wear which dominates. Last year, it was wear of the left-front which forced Ferrari onto the slower two-stop strategy after Charles Leclerc had set pole, losing him the race to Verstappen. A two-stop brings with it a theoretical race time penalty of around 15s. Ferrari were keen to stay on the one-stop this time, if at all possible.

Sainz was up for giving it a try, but a radio message from Verstappen to his team as he followed the Ferrari in the early laps sounded ominous. “He’s starting to slide a bit, so all good.” It was true. The Ferrari’s rear was sliding noticeably as Sainz tried to keep up a pace to stay ahead of the Red Bull. The higher temperatures of race day had shifted the tyre wear limitation from the front to the rear.

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The Ferrari’s strong straight-line speed was allowing Sainz to keep himself clear of the Red Bull in all the potential passing places, even though it was clear that the grippier Red Bull would easily pull away if Verstappen could find a way past. Sainz’s task was to maintain this situation until he’d pulled out enough of a gap over the field to drop into as the pit stop window opened, thereby protecting himself from a Verstappen undercut. He couldn’t get that far.

By Lap 12, the rear tyres were running out of tread and Sainz could feel the sudden loss of grip. Eventually he locked up into Turn 1, compromising his line through there and allowing Verstappen to get a better exit and thereby bring himself alongside – and on the inside – for the following Roggia chicane.

That was on Lap 15, and from there Verstappen cantered home to his new all-time wins record. Sainz later had his hands full trying in vain to fend off the other Red Bull of Sergio Perez. All this battling had left him running out of rear rubber at the end of the race as he tenaciously fought with team mate Leclerc to claim the final podium slot.

“Once Max had passed, I couldn’t even use DRS from him to ease the strain on the tyres,” explained Sainz, “because he was gone as soon as he passed. Sometimes you can manage the tyres a bit better if you get DRS because they pull you on the straight and then you can control the exits and the traction and the medium-to-high speed a bit more.

“Today I never really had the chance to feel that, and I had to push quite a lot in the corners, to try and keep that gap and defend into Turn 1, and in the end, it was just never possible for me to manage those tyres. It nearly cost me the podium.

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“It did feel more like a two-stop than a one-stop. In the end, we committed to a one-stop because that's what our numbers suggested before the race but honestly, I was probably five laps short in each of the stints. The last four laps I did on the medium, I did it with zero rubber left. And the last five I did with the hard, I did them with zero rubber left. That's why I was sliding around so much. For me, a one-stop was very tight and very on the limit.”