The start-finish straight on the run down to Turn One is slightly downhill and quite often the cars will be travelling into a head-wind, which normally picks up in the afternoon and around the start of the race. There are marker-boards on the left-hand side of the track to look out for before downshifting from seventh gear into third. There's some potential for overtaking here but the problem is that it's just too fast a corner and the braking zone is very short. The drivers will be aiming their front-right tyre onto the inside kerb to help hook their car into the corner before sacrificing a bit of speed around the turn in order to open up Turn Two. Turn Two is a tricky corner because a driver will want to carry speed and the car will want to understeer or snap out at the rear on the exit. It's then full throttle coming out of Turn Two, shifting up the gears and, depending on fuel loads, reaching fifth or holding fourth for Turn Three. Three is an awesome corner. It's extremely long and you can feel the G-Forces loading up as you continue to accelerate pretty much all the way around it. It's also part of the circuit where you really get to feel the aerodynamic balance of the car and a corner which separates the good cars from the less good - in qualifying, some cars will be able to take Turn Three at full throttle while those at the back of the grid have no hope of doing that whatsoever! The exit of Turn Three is a little bit like the exit of Parabolica at Monza in that you have to be brave and trust that the grip will still be there halfway round the corner and through to the exit - and even if you pick up a slight bit of understeer, you still have the confidence to keep your foot down and trust that the car can be recovered as the angle of the corner decreases. It's a very fine balance to get right and it's also a corner that a driver will really feel physically by the end of the race because there's such a high load of G-Force around here. The car will then be worked up through the gears on the run down to Turn Four, braking just after the bridge that crosses the track, and hugging the inside of a corner which starts off pretty tight and has a gravel trap - a common feature on this track because it's still regularly used for motorbike racing - waiting on the exit if you get it wrong. Any driver making a mistake here will be punished and, if he goes off into the gravel, potentially have his race ended as well. The exit of Four will, once again, highlight the aerodynamic efficiency of a car because getting on the power as soon as possible is vital. It's a long, winding exit that opens up as it goes up and over the crest of the hill before the track plummets at the last minute down into Turn Five. Five is a very tight left-hander where quite often we see cars lock-up their inside front because it just hangs in the air as you try to turn in. It's not especially vital, however, to hug the apex initially because the corner only really starts to tighten towards its end and the nature of the camber, coupled with the undulation, seems to mean you always seem to exit Turn Five in the same time - you never seem to gain or lose much here. It's quite a bizarre corner, although it's potentially an overtaking spot if the car in front gets it wrong on the exit from Four. A little bit of the kerb on the exit can be used out of Turn Five - but not too much else the car will break into wheelspin - as the track falls downhill through the kink of Six and into Turn Seven. This is quite a challenging chicane to get right because it's easy to lock the inside left-front into Seven and you then use all of the available run-off area on the exit of Seven which then becomes the apex of Turn Eight - this section of the track is very much a left-right flick. It's vital to carry speed out of Turn Eight, even though the car can become quite lively here, as the track climbs up the hill towards what's one of the best, if not the best, corners at Barcelona. Turn Nine is a ninety-degree, fast right-hander which is taken in fifth gear - or fourth, depending on fuel load - for an aggressive turn-in. A driver must trust the car here, and use all of the track available, with the apex at the crest of the hill. It's a corner where a driver has to trust the grip, keeping his foot down, even if, as is normally the case, the car slides a little on the exit, taking you onto the rumblestrip. It's a corner where time can be won if you attack it constantly through the race - although by the end of the race there's generally just a single line because of the marbles. It's also an important corner to get right because it leads on to a relatively long straight and what I'd say is the second most realistic overtaking opportunity on the track. Turn Ten is a very tight, left-hand hairpin for which you brake just before the 100 metre-board, changing down into second or first gear depending on fuel loads and car balance. It's important here not to run out onto the asphalt turf as doing that will definitely upset the traction because you're going so slowly. That then leads into Turn Eleven, which is quite a frustrating corner because the car doesn't quite have enough downforce to be properly stabilised and, running in third gear, you're vulnerable to the rear snapping out if too much is asked of it. Coupled with a kerb on the inside that has to be ridden, it's a corner which sometimes has to be backed out of - especially on heavier fuel - to resettle the car and one which will quickly erode confidence if you are suffering from severe rear degradation. Even as you are still turning left on Eleven, you have to brake and feed the car into the long, long right-hander that is Turn Twelve. It's a corner that goes on for so long that it feels like you are on a roundabout, waiting and waiting until you have enough grip at the front to feed the power in. You're at the mercy of your car's understeer here - and patience is the only way to deal with it. A few years ago, a driver would be increasing his car's speed out of Twelve, rolling up his sleeves readying himself for a fight around the final two corners. But nowadays, just as you are gaining speed, you have to slow it all back down again to feed the car back into Turn Thirteen, which has a huge kerb on the inside at the apex that, if touched, will spit you offline and possibly even off the track. A little more of your remaining speed then has to be sacrificed around Thirteen in order for the car to be brought back over to the right-hand side of the track and the best approach for Turn Fourteen, which is a very slow corner. Fourteen then leads into the equally-slow Turn Fifteen. It's a frustrating part of the track. You can't overtake here, you can't gain much time here, and the cars feel lethargic and cumbersome - as if they are being asked to do something that they don't want to do. On the exit of Turn Fifteen, it's common to suffer wheelspin, forcing you to stay off the kerb on exit, and you approach Turn Sixteen - the final corner of the track - expecting to take it at full throttle whereas, in the old days before the circuit's redesign, it used to be a big-balls corner that required either a little tap on the brakes or a little lift before putting your foot down on the throttle. Nowadays, you just drive through Sixteen full throttle every time, regardless of whether it's qualifying or the race. Sadly, the fiddly chicane of Thirteen-Fourteen-Fifteen has taken away the fun and challenge of what once was a seriously impressive corner. And through Sixteen, you're back on to the main straight, passing a huge grandstand on the left-hand side...and that's another lap of the Circuit de Catalunya completed.