Colton Herta drove Sergio Perez's Cadillac in first practice for the United States Grand Prix on 23 October, the only driver in the session without a race seat. It was his fourth rookie outing of 2026 and his third in Perez's car. Cadillac's count did not move: the team still owes a run in Valtteri Bottas's car.

Article B1.7.3 of the 2026 Sporting Regulations, Issue 09 sets the count. In FP1 or FP2 at two Competitions, for each car entered, every team must use a driver who has not taken part in more than two Championship Races. Eleven teams with two cars each makes 44 runs a season, two per car, and a third run in the same car pays off nothing.

Reading the FIA's classification for every practice session that could carry a rookie run, 30 sessions over 18 rounds, puts 24 such runs on the board. Each event's entry list names the extra drivers a team may use, and those lists match the classified rookies at every round but one. Cadillac's surplus run leaves 23 that count, so on the rule's wording the grid owes 21, almost half the season's total, with Mexico City, São Paulo, Las Vegas, Qatar and Abu Dhabi left on Formula 1's calendar.

Team Runs counted, by car Owed
McLaren Norris 1, Piastri 1 2
Mercedes Antonelli 2, Russell 0 2
Red Bull Hadjar 1, Verstappen 1 2
Ferrari Leclerc 1, Hamilton 1 2
Williams Sainz 1, Albon 1 2
Racing Bulls Lawson 1, Lindblad 0 3
Aston Martin Alonso 2, Stroll 1 1
Haas Ocon 1, Bearman 1 2
Audi Bortoleto 1, Hulkenberg 1 2
Alpine Colapinto 1, Gasly 1 2
Cadillac Perez 2 (3 run), Bottas 1 1

Monza on 4 September was the last Friday that reduced the total. Ayumu Iwasa took Max Verstappen's Red Bull, Luke Browning had Alex Albon's Williams, Paul Aron had Pierre Gasly's Alpine and Herta had Perez's car. Madrid, Baku, the Bahrain Grand Prix held at Sepang, Singapore and Austin followed with one rookie appearance between them, Herta's surplus run on 23 October.

Most of the season's runs came in three June and July weekends. Barcelona and Austria carried six each and Hungary five, 17 of the 24 runs; Barcelona was where Leonardo Fornaroli, Aron and Browning were named for their first outings of the year. Aston Martin went early and is nearly done: Jak Crawford drove Fernando Alonso's car in Japan and Belgium and Lance Stroll's in Austria, the last of them at Spa in July. One run in Stroll's car remains.

Mercedes has run Frederik Vesti twice, at Barcelona and Hungary, both times in Kimi Antonelli's car. George Russell's car has never had a rookie in it, and the rule counts cars, not teams, so Mercedes needs two of the last five rounds with Russell out of his own car for a practice session.

Racing Bulls owes the most, three, and the figure turns on a reading. Arvid Lindblad started the year without a Grand Prix to his name, so in his own car in Australia, China and Japan he met the career test of B1.7.3. The text in force in March, Issue 05, set the obligation inside a permission to use "additional drivers" in practice, and Issue 09 has the rookie use "the power unit and tyres which are allocated to the nominated driver they are replacing". On both wordings Lindblad's own sessions do not count, and only Iwasa's Austrian run in Liam Lawson's car does. If the FIA treated Lindblad's early sessions as rookie runs, Racing Bulls would owe one and the grid 19.

Issue 09, approved by the World Motor Sport Council on 30 September, tightened what a run must be. Issue 08 carried the obligation as one sub-clause of the extra-driver rule, with a seven-day notice naming the driver and the car. Issue 09 gives it its own article, adds the session to that notice, and requires the rookie to take the nominated car out of the pit lane at least once in that session. It also says no other driver may take that car out of the pit lane during that session.

Barcelona shows how a nominated run can be lost. Williams put Browning down for Albon's car in first practice on 12 June, and he never reached the track because of an electrical problem with the FW48. Neither name appears in the FIA classification for that session, and the run did not count. Under Issue 09 a repaired car could not then go back to its race driver for the rest of that session, and a fresh notice is due seven days before whichever round the team tries next.

Five rounds leave little room for a second Barcelona. Mercedes in Russell's car and Racing Bulls in Lindblad's each need two of them, so either team can lose three rounds at most before the count is out of reach for that car. Mexico City is next, and nine of the eleven teams arrive owing two runs or more.