One only has to look at the timesheets from this morning's session and this afternoon's to see that following the lunch break quite a few drivers failed to improve.

As the final pre-season test reached the halfway point, once again we were left with - for the most part - more questions than answers.

Mercedes continues to be the best, the Silver Arrow not missing a beat. This morning Valtteri Bottas raised the bar ever higher, posting the best time seen since testing got underway.

While Lewis Hamilton notched up the laps this afternoon, bringing the German outfit's tally to 149, twice, as he looked set to go out on a fast run, he was frustrated by red flags.

The first was when Kimi Raikkonen spun off into the barrier at the exit of Turn 3, breaking the front wing of the Ferrari and damaging the suspension, the second when Verstappen pulled to the side of the track at Turn 13.

“That's frustrating," admitted Mercedes, "Lewis had just cleared 77 laps for the afternoon."

Though Hamilton failed to challenge his teammate's time, assuming that was the intention, he did put together an impressive run on the ultrasofts

“That was a long run on the ultrasofts from Hamilton,” admitted Pirelli, “he just completed 20 laps. Interesting preparation for Australia.”

Despite all the talk of overtaking, at one stage Hamilton came across Verstappen, who was on his race sim. The Briton, who was on ultrasofts, made very, very short work of the medium-shod Red Bull driver.

So while the Mercedes steamroller carries on regardless, what of the opposition.

Well, it was another good day for Williams. Felipe Massa completed 63 laps this morning, posting a best time just 0.110s off Bottas' pace, while Lance Stroll kept it on the black stuff this afternoon and added another 59 laps to the team's tally on his way to fifth.

Raikkonen's spin this afternoon was his second of the day, thought the first appeared to have more to do with the amount of baggage his car was carrying, the rear end of the SF70H looking as though the CIA was gathering info from every Samsung appliance in Spain.

Following that particular off, the Finn was in the garage for almost two hours, Ferrari revealing it was checking the fluid system.

Having retrieved the car following his more serious off, the Maranello outfit quickly covering the car with the ever present tarpaulin, it tweeted the news... “no more running for Kimi today,” missing out the bit about “and no dinner either!”

Max Verstappen will have plenty to talk about tonight. Having lost three hours of running in the middle of the day after it was decided to change his engine, the Dutch youngster all but managed a race simulation this afternoon, before grinding to a halt with just a couple of laps remaining.

Frustrating yes, but still Red Bull must be happy with the pace and feel of the car up until that point.

While Red Bull has made much of the fact that its 2017 contender is the RB13 - which, as it happens stopped at Turn 13 today - it will be Jolyon Palmer and Renault who will be keeping an eye out for black cats and the like.

Having lost much of yesterday's track-time, this afternoon, while teammate Nico Hulkenberg completed 61 laps this morning, the Briton could only manage 29. Definitely a mixed day for the French team.

Compared to others, Force India, Haas and Toro Rosso will feel their day was pretty uneventful, in each case their drivers (Perez, Grosjean and Sainz) putting in a decent amount of laps albeit all around 2s off the pace.

A decent, if uninspiring, day for Sauber also, where Pascal Wehrlein completed 59 laps this morning - the German clearly fully recovered from his back pain - and Marcus Ericsson another 47 this afternoon.

Unfortunately, the Swede ground to a halt at T8 in extra time - the session having been extended by 5 minutes following Verstappen's red flag - causing officials to abort the remaining few minutes.

And then there's McLaren.

We await the official description, but we're sure the words 'valuable' and 'learning' will appear - which reminds us of an old Ken Dodd joke.

Over the course of the day, Fernando Alonso completed 47 laps, posting a best time 4.074s off the pace.

While there were no engine changes, there were lots of single lap runs, which must be as frustrating for the driver as it is for the fans.

Having completed 27 laps in the morning we were expecting a flurry of activity after lunch. However, over an hour into the afternoon, with no sighting of the Woking car, Honda revealed: "Alonso will be out gathering aero data, testing tyre compounds and mapping the power unit.”

True to his word, the Spaniard did appear, but over the course of the next couple of hours there were no further improvements and only another 19 laps on the board.

The situation became even more bizarre when at one stage the McLaren was seen being pushed down the pitlane with its driver nowhere in sight… places he would rather be, anyone?

Mind you, the Spaniard still has his sense of humour. Asked if he expects to take Turn 3 flat-out, he told journalists: “With our lack of power, we can take every corner flat-out!”

Come on, if he didn't laugh he'd be crying.

Weather: overcast; air 12 degrees C – 22 degrees , track 13 degrees C – 27 degrees

Check out our Wednesday gallery from Barcelona, here.