The NBA has tipped off, meaning I’m watching a lot more basketball recently. A concept that most NBA offenses use a lot in recent history is the isolation, or “iso,” play.
An "iso" play involves isolating a single offensive player by giving them the ball and clearing their teammates out of the way. This sets up a one-on-one (1v1) scenario, where the player in possession attempts to score against their defender without immediate help from others.
Inspired by this idea, we're borrowing the concept of isolation plays and applying it to football analysis, focusing on moments where players find themselves in 1v1 situations and examining their impact on game outcomes.
Defining 1v1s (Iso):
Put simply, a 1v1 occurs when an offensive player faces a defender one-on-one, with potential help defenders either too far away or too occupied to help.
Using StatsBomb 360 data, we define a 1v1 as a reception where the nearest defender is more than 3 yards away, and the second-nearest defender is more than 7 yards away.
There’s no specific reason for choosing 3 and 7 yards—just video reviews that made these thresholds seem reasonable.
This definition has flaws: it doesn’t take into account what the 2nd defender is doing, whether they’re occupied or not, what the phase is (transition, etc), but it’s a start.
Are 1v1s important?
A lot of football tactics is trying to move the opposition around so your best (and usually most dribbley) players can get time and space to attack defenders.
“Much of Guardiola’s work around this concept (1v1) seems focused on teaching the team how to create more, and better, opportunities for this situation to occur” (link)
So let’s try to find out if they actually lead to good things happening.
We’ll be using Statsbomb’s OBV model to measure if 1v1s lead to success.
OBV is a model that measures every action on the pitch and how much it added to the probability of scoring or conceding for your team.
For every normal and 1v1 reception, we’re measuring the maximum OBV reached within 15 seconds of the reception and comparing it with OBV at time of the reception, to figure out if a team’s probability of scoring has gone up.
"If 1v1s are valuable, we’d expect their effectiveness—measured as the difference between Maximum OBV within 15 seconds of the reception and the prior OBV—to exceed that of non-1v1 situations
(In simpler terms, this means that normal receptions get a 2.4% bump within 15 seconds and 1v1 receptions get a 2% bump of scoring goals within 15 seconds)
At first glance, 1v1 opportunities appear to be negative, with lower effectiveness than non-1v1 receptions.But if we filter for only final third receptions, the 1v1 value starts to show:
If we split it by zone (attacking from right to left), you start to see the trend, 1v1s are net negative in your own half and hugely positive in the opposition final third.
I’m unsure why 1v1s are net negative in your own-half. Perhaps it speaks to a lack of passing options, or it shows that losing the ball in your own half is more negative than the 1v1 opportunity.
In the final third though, it seems that 1v1s are very valuable, especially closer to goal, which fits intuition quite nicely!
Where do 1v1s happen?
As expected, 1v1s get more rare as you get closer to goal and more central. Only 7% of final third receptions are classified as 1v1, and only 3.6% of central final third receptions are a 1v1 opportunity.
Here’s Arsenal, the team with the lowest frequency of 1v1s in the final third:
And Bournemouth, the team with the most 1v1s (final third) in the EPL
Which teams rely on 1v1s?
Red vs. Green is how good the attack is without 1v1s.
X-axis is how often the team is in 1v1 opportunities
Y-axis is how much better team is in 1v1 opportunities vs. normal offense
Quick Takeaways:
United, Villa, Liverpool, PSG are much better in 1v1s than their normal offense.
Barca, Milan, Madrid are not much better in 1v1s than normal receptions.
Arsenal, Leverkusen rarely play in 1v1 scenarios, Inter, Liverpool, AC Milan play a lot in 1v1 scenarios.
On defense:
Green vs. Red is how good the defense is without 1v1s. (Red is better)
Leipzig are weird? never in 1v1s and bad at defending them.
Juve are good at defending in both 1v1 and normal
The only way to hurt Madrid, Atletico and Arsenal is through 1v1s.
Which players rely on 1v1s?
Notes:
Fullbacks get a lot of their receptions as a 1v1 in final third, which is intuitive. (Digne, Raum, Trippier, Lucas Vazquez, DiMarco, Gusto) all in top 10. None of them seemed to use it very well except for Dalot and Carvajal.
Among high-volume players, Mbappe, Rashford, Foden, and Bailey emerge as the best 1v1 threats, validating this metric.
Other names with good metrics here (not shown): Son, Saka, Coman, Lino.
If we make the cutoff 25 1v1s the top in efficiency are:
Rashford
Mbappe
Foden
Alvaro Garcia from Rayo
Jonathan Clauss from Marseille
Bailey
Saka
…which seems pretty good.
This could be a good metric to try to proxy which players were overly reliant on 1v1s for value creation:
Rashford
Kounde
Frimpong
Dalot
Coman
and less reliant on 1v1s:
Saka
Salah
Yamal
Bailey
Grealish
which also feels like it makes sense, the latter list seems better in smaller spaces.
Feels like this is a useful quick player profiling tool.
Passers that make 1v1s:
Bruno and Rodri lapped the field both in terms of volume and frequency.
Odegaard, Maddison, Barella, Gundogan, Kroos obvious metronomes for their teams.
Saka, Yamal, Rodrygo, Mitoma, Salah the dribblers that operate in small spaces where all their passes are in tight corridors?
Real Madrid Case Study:
One extra way we can use this data is to look at whether one side for a team is particularly vulnerable to being bypassed.
Looking through the data the team with one of the highest discrepancies between sides is Real-Madrid, who allow 1.4% more 1v1s down their right-hand side (opponents left) than their left hand side.
Could be due to their attacks going more down the LHS and so the counter-press is ready there, could be lack of a real RW, could be plenty of things, but it does seem the RHS is more vulnerable.
Conclusion
Overall, a promising start to a simple metric. Next steps seem to be: getting rid of set piece phases (lots of short corners lead to artificial 1v1s), and figuring out a way to proxy 2nd defender is busy.
We’ve also mildly confirmed a few things we already knew:
Villa Liverpool, United depend heavily on 1v1s (perhaps in their transition-heavy game model
Arsenal and Madrid’s deep blocks are hard to crack, better to try to catch them on the counter for 1v1 situations
We’ve found some 1v1 reliant players (Rashford) and some much less so (Yamal)
We’ve found some wingers with 22% of receptions in 1v1 (Doku) and some with as low as 10%, hinting at different roles
And we’ve learned that Rodri, Bruno and Kimmich are good passers and help their teammates get 1v1s