Malaysian Grand Prix qualifying and the race are set to be turned into strategic thrillers thanks to the high degradation of tyres witnessed at Sepang so far, reckons Pirelli.
With the hot temperatures and abrasive track surface leading to high-wear rates, the indications after opening practice in Malaysia are that teams are going to need to be at their tactical best in both qualifying and the race if they are to achieve success.
With early predictions suggesting the soft tyre is only likely to last for around eight laps if they are qualified on and then raced, it means at least a three-stop race for those opting for the one-second advantage that the option tyre could bring in Q3.
However, if track evolution can be stretched up to 20 laps for the hard tyre, then there is the possibility that those starting on hard may be able to get away with doing one less stop - which could hand them a good advantage in the race.
Speaking to AUTOSPORT after analysing the Friday data, Hembery said that the tyre situation was on course to produce major excitement.
"I think on average we are going to see three stops, and I would be surprised if it is four," he explained. "This is only Friday and we've got full running tomorrow and in the race, so things can change.
"In Melbourne, we saw quite a rapid evolution of the track, although I am not sure if that was representative. But, at the moment, you are looking at 12-14 laps on the hard tyre - with some evolution to arrive at 18 laps. That brings you pretty close to a three-stop strategy. You will probably also get some people who will try and two-stop.
"This circuit is tough. With a 50-degrees asphalt temperature, aggressive wear, it means that the degradation is more than what we saw in Melbourne for sure. But equally it is pretty close to what we were trying to create.
"If you are an engineer working for a team you probably don't want that, as the balance of your car is changing through the race and through the stint, where there are fuel loads changing as well. But from our point of view, it is pretty much in line with expectations."
Hembery reckons that the one second time difference between the soft and the hard tyre, allied to the degradation situation, was enough to leave open the possibility of outfits sacrificing grid position for the more durable tyre.
"The gap between the compounds is one second, up to 1.2 seconds - which is good actually," explained Hembery. "That will lead to the qualifying question - and there is definitely a choice to be made now.
"Maybe Red Bull might have a different strategy because they can think in a different way [as their car is so quick], but I think everyone else would have to qualify on the soft.
"Most people tried the soft in the afternoon session and were doing a chrono lap. Some were then trying to back off and go again, which seemed to work for a few drivers.
"At the moment you are looking for eight laps. I don't know when they would use the soft, either right at the start or right at the end, but it would be a three-stop strategy with that level of wear if you started with it."
Hembery said he was also not unduly concerned about the high level of marbles that were seen on the track during Friday's running - and he said the situation was different to that witnessed in pre-season testing.
"They are slightly different," he said. "We had strips in winter testing, big strips. These are actually smaller pieces that actually get picked up on the tyres. We haven't been able to tell if they actually wear off.
"Some of the cars picked it up on the in-lap, but it would have been more interesting if they had done that and carried on going around, then we could see what the wear off rate is.
"That is something that we are going to have to look at tomorrow, but it is a big wide circuit. There should be plenty of opportunity to overtake and there should not be an issue with the marbles.
"But we will go out tonight, wander around and see the marbles. It hasn't been highlighted to us in a great way. There is high wear, so there is bound to be material coming off the tyre.
"It has to go somewhere; they cannot all go down on the racing line so there will always be a high level of material coming off the tyres. It is just if that material then causes an issue regarding the racing."