let's have a quick look at something
that's mentioned a lot a sort of taken
for granted but never really explained
the undercut I'm doing a race you'll see
two cars racing closely within a few
seconds of each other maybe the chasing
car turns to a common stretch to use
these times of Tire domination the
undercut now stop earlier than their
competition in the hopes of gaining an
advantage as the chasing car stops the
two are temporarily separated until the
leading car takes their pit stop taking
the pit stop slightly later is a
disadvantage when the car exits the pits
the final competition is managed to jump
them the chasing car successfully
Plumley undercut and taken the lead well
why does this work what's actually going
on here well let's take a look at the
lap times in this kind of area of f1 the
lap times are dominated by the
performance of the tires the tire at
their best went fresh with each passing
lap the tires continue to degrade and
the drivers lap times grow and grow on
this chart were looking at now each bar
represents one lap the bars getting
longer and longer showing the driver is
taking a longer time to complete each
lap I've exaggerated it here just to
make it a bit clearer so when the driver
pits and steps on some fresh tires
they'll then come out and push their car
to the limit again the lap times are now
immediately shocked they're able to go a
lot faster on fresh tires chasing car up
to the pit stops is blue very similar
lap times the car it's trying to catch
but they go for the undercut based on
one map earlier they were able to put
down faster laps one lap earlier - and
as the cars are matching each other for
pace before the stops let's make this
absolutely clear by focusing in on those
crucial laps around the pit stops
if we take the lap time bars and stack
them all in a row this gives us the
total length of time for the first car
to complete laps 9 to 12 put in the lap
times of the second car
the undercutting car along side is clear
is able to put in an extra fast lap
through the pit stop days and those four
laps have done much faster than the four
laps of the car that stopped later of
course we have to include the time it
takes to take the pit stop to wonder G
will gain can extend the pit stop I mean
the difference in winning and losing so
let's have a quick and dirty look at how
we can start to calculate the race
strategy the time across a spin Bay is
the time between stops it's just the sum
of lap times investment plus the pit
stop lost time the other lap times will
tend to increase through this thing as
it tires degrade so let's take the tire
as its freshest the fastest and call
that the baseline lap I'm talking mostly
about tires here is they by far the most
dominant factor in lap strategy but if I
want to be thorough let's just remember
that track temperature fuel weight which
actually decreases lap times as the fuel
is burned off through the race rubbing
in of the track and many other factors
all to affect our lap so more varies
from this baseline but for now let's
stick with the basic fact that lap times
will get longer and longer across this
thing as tires degrade so we could say
all of this time here is the time we've
lost over to stick the tires to grip
with each passing that we're losing more
and more time compared to the baseline
fresh tire lap also in each dip is the
pitstop time here again I super
exaggerated it just so I can illustrate
something clearly for you the question
is over the length of the whole place
how does the total time lost due to tire
degradation compared to the length of
time it is to get in those extra pit
stops
let's build on this to construct a
picture over the whole place let's
separate out these base them based lap
times from the time lost each map and
remember our pit stop time so just
looking here
orange is baseline that blue is the time
lost and green is the pit stop time this
is what this brace looks like over its
entire course and it's not a simplified
version we've got series of laps
including the time loss each lap
separated insistence by pit stops this
is a two-stop strategy we can bring in
variation using two stops after just
three steps split by two stops we've
learned a three-stop strategy if we won
putting in more stops minces fewer laps
between pit stops which means in each
didn't been able to push harder through
the stints this is more aggressive if
you can pull off the strategy the total
race time ends up being much lower
this is individual lap is much quicker
the question is how much total time is
saved compared to taking that extra pit
stop after pushing a lot more there is a
greater risk of making mistake and a
much greater risk of using up the tires
and field too quickly so we have to
takes into account as well alternatively
we could take less pit stops to pull
this off we have to take it much easier
each lap the lap times are now slower
but are they so slow they would be
easier and quicker just to make another
pit stop instead these are the kind of
things to think about when we're
planning our range strategy ahead of the
race the course typically softer ties
will be used on shorter stints and
harder ties will be used to manage the
longer stints most three strategies of
course a mixture of different soft
masses of tires and the effects here
will be sort of a mixture of short
stints and long sticks and it's really
just a matter of adding up baseline maps
the time lost due to degradation and the
time lost you to making pit stops this
is a very simplified version of things
but it kind of gives you an idea of how
strategies come together and how an
undercut could really make the
difference hope you enjoy this video I
plan on making more as I come up with an
idea of how to explain something
thank you for your suggestions of what
kind of things you'd like to see
explained I'll try and get them as and
when I can I know these videos are quite
far apart I look forward to seeing how
you think of this one and continue to
let me know what else you'd like to see