Formula 1's rule book has expanded massively over the years, and has got increasingly more complicated as new regulations have been added or evolved.
One consequence of a constantly changing rule book is that sometimes rules can end up contradicting each other – or a clause aimed to stamp out a certain design gets made irrelevant.
This is something that happened with the 2017 floor rules, as a regulation originally intended to stop teams exploiting holes in the floor was made inconsequential.
That's because when the floor width was increased from 1400mm to 1600mm last year, a separate clause banning teams from having holes 700mm from the car's centreline was suddenly made irrelevant.
Teams quickly realised that without it being updated to reference an 800mm lockdown, there was a 100mm area on the edge of the floor where they were free to utilise holes again.
And it is Ferrari that has led the charge, with the most complete concept in perfecting the holes in the floor evident on its 2018 car (see below), although other teams are now copying in their own unique ways.
The value of the holes
The use of slots or holes ahead of the rear wheel are used to combat 'tyre squirt' and improve diffuser performance – and all teams now make use of them to a greater or lesser extent.
The rotation and deformation of the rear tyres put the surrounding airflow into a constant state of chaos, resulting in airflow being pushed - or 'squirted' - laterally into the diffuser's path.
Left unchecked, this robs the diffuser of peak performance and creates inconsistencies, both of which impede the driver's progress.
For years now, designers have sought ways of controlling the turbulence created by the rear tyres, utilizing various floor shapes, holes, slots, strakes and even exhaust gases in order to sculpt the airflow's direction whilst also enhancing the diffuser's edge vortex.
For teams, the difference between a slot and a hole may appear inconsequential to the eye, but the difference in performance between a rigid hole and a slot that loses performance as the floor deforms under load can be quite big.
As an example of the performance on offer, Ferrari ran several iterations of these slots during 2017, numbering anything from three to six slots with various lengths and angles used in order to deal with the given circuit characteristics.
The last team to run fully enclosed holes in this area of the floor were Red Bull in 2012 (left inset), when in quite controversial circumstances its design helped the team win in Monaco.
That victory prompted unease from some of its rivals and there were threats of a post-race protest, but in the end the other teams did not see that through.
However, the FIA's stance was subsequently clarified over what would be considered legal, a situation that led to the slots we've come to know.
The last Ferrari to use fully enclosed holes ahead of the rear tyre was the F10 from the 2010 season, latterly used in tandem with its exhaust blown diffuser.
While Ferrari is not the only team to utilise the enclosed tyre squirt holes – as a glance down the grid shows most other teams are doing so also – it is the only team that has specifically designed its cars around this concept.
This is far from an optimised solution though and means that Ferrari has stolen a march on its rivals in the short term.
However, expect Ferrari's rivals to come up with more bespoke solution when the raft of major updates appear from the Spanish Grand Prix.