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+---- Thread: *Home field advantage - An Analysis (/showthread.php?tid=21107)
*Home field advantage - An Analysis - IthicaHawk - 04-13-2020
Home field advantage - An Analysis
I noticed during the season that my team seemed to be winning significantly more often at home than away. At the end of the season I decided to take a look and see if that was the norm.
![[Image: RGAarMO.png]](https://i.imgur.com/RGAarMO.png)
Fig 1 - DSFL S21 home vs road wins
Yikes, that's a big difference. Teams win, on average 1.7x more often at home than on the road. Not only that, only one team (London Royals) dropped more games than the highest number of road wins across the entire DSFL.
How about the NSFL I thought, lets take a look at the S21 NSFL season
![[Image: 7esTGKt.png]](https://i.imgur.com/7esTGKt.png)
Fig 2 - NSFL S21 home vs road wins
A little bit more parity than the DSFL shown here in fig 2 but not much. Teams are still 1.4x more likely to win at home than on the road. The difference in the NSFL of lowest home wins vs highest away wins was also quite different.
Liberty managed, in fact, to defy statistical analysis and not only win more on the road than at home but fully 2x more on the road (1 home win vs 2 away wins). A feat not seen since the S16 Yetis who racked up 0 home wins vs 1 away wins.
Speaking of S16. That is the season the NSFL expanded to it's current teams so put in the numbers for each season, S16 to S21 of the NSFL and graphed the results, shown in fig 3.
![[Image: n7emVPX.png]](https://i.imgur.com/n7emVPX.png)
Fig 3 - NSFL S16-21 home vs road wins
We see much the same throughout the last 6 seasons. Teams, on average, win at home 63.97% of the time vs only 36.51% on the road. Not quite double but 1.75x more home wins than road wins is certainly evidence of a strong advantage.
Over the last 6 seasons there were a number of standouts:
- Four teams went undefeated at home*1 but still managed to only win an average of 47.62% on the road.
- No teams went undefeated on the road, the closest we saw was the S16 Wraiths who went 5-1 on the road (83.33% win rate)
- Three teams lost every road game in the season*2 but usually paired that with a home win rate of >50% except the S16 Copperheads who declined to win at all that season, stats or no stats.
The next step is to consider if this is normal in the greater word of sports. Analysis conducted by Jeremy P. Jamieson at Northeastern University*3 suggested that, not only did the home field advantage exist across other sports leagues, it matched very closely to what we see in the NSFL.
In his study across a number of sports leagues including the Premier League, Rubgy, NFL, NBA and more, Jamieson indicated that the average home field advantage win rate was approximately 60.4%. The closet relation to the NSFL with 63.97%, the NFL showed a home field advantage of 57.3%. Compare this to soccer, at 67.4%*6.
In the NSFL, we have each team playing 13 games. Could this be a factor? Jamieson did study the effect of season length and concluded that, as season length increases, so home-field advantage decreases*4. Per these findings, the winning percentage at home for sports with more than 100 games was much smaller at 55.9% vs sports with less than 50 games at 62%*5.
Conclusions
It can be concluded that, yes, the NSFL does have a reasonably significant home field advantage with the home teams 1.74x more likely to take the W. It can also be concluded that this advantage roughly fits with what could be considered 'normal' within the wider world of sports although definately on the high end of normal.
One factor we discussed was season length so it could be postulated that, as the league expands (in both teams and number of games played) we would expect to see the home field advantage diminish. Are there other factors that can be tweaked within the simulation itself to reduce the effect of home field advantage in the NSFL? Possibly. Should we? Probably not. With a limited number of games each season and only 6 seasons with the current roster of teams, these stats can be effected quite significantly by one or two outlaying season performances. I would suggest continuing to monitor the home field advantage to see if it trends towards the high 50%s rather than swings away from that.
If S22 is as balanced as S21 (57.86% home win rate) then we have absolutely nothing to worry about.
*1 - S20 Wraiths (7-0 / 2-4), S18 Wraiths (6-0 / 5-2), S17 Hawks (6-0 / 2-5), S16 Butchers (6-0 / 4-3)
*2 - S20 Butchers (4-2 / 0-7), S19 Butchers (3-3 / 0-7), S16 Copperheads (0-6 / 0-7)
*3 - The Home Field Advantage in Athletics: A Meta-Analysis - Jeremy P. Jamieson - Link to PDF
*4 - 1832 - The Home Field Advantage in Athletics: A Meta-Analysis
*5 - 1839 - The Home Field Advantage in Athletics: A Meta-Analysis
*6 - 1836 - The Home Field Advantage in Athletics: A Meta-Analysis
*Home field advantage - An Analysis - infinitempg - 04-13-2020
Holy shit he brought footnotes and receipts. This is awesome! We always complain about HFA being very overpowered in this league, so it's interesting to see that it actually matches up fairly nicely to the real world.
*Home field advantage - An Analysis - iamslm22 - 04-14-2020
wow! what a great article. Good work!
*Home field advantage - An Analysis - Duilio05 - 04-14-2020
(04-13-2020, 09:52 PM)infinitempg Wrote:Holy shit he brought footnotes and receipts. This is awesome! We always complain about HFA being very overpowered in this league, so it's interesting to see that it actually matches up fairly nicely to the real world.
You trying say HFA is no longer a reasonable complaint for why a team looses?