Red Bull has been desperate to find an alternative to Renault engines in the V6 hybrid era. Toro Rosso's rapid progress in 2018 suggests it may finally have a viable option, but it's still loaded with risk…
Stick or twist? This is the question Red Bull must answer as it considers whether to continue to use Renault or switch to Honda propulsion in 2019.
When the deal was first done for Toro Rosso to become Honda's works Formula 1 partner last year, this seemed an optimistic hit and hope with a low probability of paying off, but Pierre Gasly's fourth place in the Bahrain Grand Prix proves it has become a more serious proposition.
Bahrain was just one performance and, even in the back of a car produced by one of F1's more modest teams, a gap of almost a second in qualifying to the Red Bull-Renault does not represent a miracle.
But it suggests Honda is making real progress and the performance gap between it and Renault is narrowing.