Week 16:
Beatpaths.com
Have you ever wanted an easy graphical description of exactly how a sports season has played out? If you had that, you could get a clear intuitive sense of how well a team has been playing and where that team is in performance in relation to other teams. There's a new system out there called Beatpaths that does just that. It shows who has beaten whom, who's convincingly better than whom, and where the pecking order is still ambiguous. It's based entirely off of wins, losses, and schedule.
How does it work? Basically, the system draws an arrow from each team, to each team that it has a "beatwin" to. By ordering the graph vertically, the teams tend to organize themselves vertically, and you start to get a sense of the overall team hierarchy.
Sounds simple so far, right? There's one obvious complication, however, and this is where the Beatpaths system has found an innovative and elegant solution: what happens when there's a loop?
It's all too common - we've all entered in arguments about win loops, especially with college football. San Diego beat the Colts, so they're better! But, the Colts beat Pittsburgh, who beat San Diego, so they're better! It's circular, it's confusing, it's annoying, it's a beatloop.
The truth is that beatloops don't really tell us anything at all. If a team is in a beatloop with another team, it simply means that the relationship between those teams is ambiguous. In the Beatpath system, since we have so many other points of connection, the other win-loss data will give us more than enough information to determine a team's performance level. So, to deal with beatloops, we simply remove them. By removing a beatloop, the loop's wins and losses disappear from the graph.
Through a meticulous process of removing beatloops in the appropriate order, and continuing to recalculate the graph until no beatloops remain, we're left with each team's "beatwins", and a clear hierarchical sense of the quality level of the teams in the leagues, as evidenced by their win/loss performance.
Beatpaths.com regularly reviews the state of the NFL using beatpaths graphs. We also develop power ranking systems that put all the teams in one linear order without contradicting any beatpaths. What results is an entirely objective power ranking system that is based off of nothing other than wins and losses.
It's surprisingly accurate for what it is. Such a system will never rise to the accuracy level of what the bookies use, but our current tiebreaking algorithm is hovering around the 65% range for win-loss pick accuracy. When you consider that the system pays no attention to home field advantage, and suffers the obvious disadvantage of the sparse data from the first two weeks of the season, that's pretty good. When applying an experimental "boost" for the home team that still doesn't make any team-specific adjustments, we can usually wring out another percentage point or two.
How can you use the Beatpaths system? It's great for a gut check. When we get emotionally attached to certain teams, we have a tendency of liberally applying asterisks to our team's losses, and over-inflating their wins. In reality, a win is a win is a win, and every game counts. For instance, it's probably a surprise to Oakland fans to realize that Cleveland had a beatpath to Oakland, even before they "upset" the Raiders this week. The Beatpaths system picked Cleveland to win.
By checking out the Beatpaths graphs, you can get a general sense of which team has been performing better throughout the season in terms of wins and losses, and where they sit compared to other teams. From that point, you can apply your own judgments of home field advantage, injuries, matchups, and momentum to come up with your win/loss pick.
What's upcoming for the NFL Season? Since two weeks ago, Beatpaths has been
projecting both Carolina and Washington to experience a resurgence, with
Dallas ending up ranked behind six or seven other NFC teams (missing the
playoffs if beatpaths were used to determine playoff seedings). This week,
it appears that AFC teams will hold almost all the top slots of the
rankings. Also, Seattle's weak schedule in the final month has them falling
a few slots.
Here is the beatpath graph for Week 15 of the 2005 NFL Season. The
Beatpaths Power Rankings use this graph and a tiebreaker called "strength of
beatwins" to determine the linear rankings. We use the power rankings to
determine picks. Among the key games for Week 16 (game 15):
- Atlanta at Tampa Bay: Tampa Bay is favored. If Atlanta wins, they regain
credit for their win over the Jets, which won't help them much, but every
little bit counts. If Tampa Bay wins, they develop a beatwin to Atlanta.
Pick Tampa Bay for having a much stronger season so far.
- Giants at Washington: Washington is favored because the Giants haven't
been considered a top-tier team ever since they lost to Minnesota. While the
Giants probably don't need this win for the playoffs, they're not as strong
a team as their record indicates, and they'll need a win to answer some
questions about their quality. If the Giants win, they'll develop a beatwin
to Washington and finally be convincingly better than all four NFC East
teams. If Washington wins, they'll split the season series, and a major
dynamic will reappear in the graph: Washington will regain credit for their
earlier win over Seattle, and Seattle will regain credit for their earlier
win over the Giants. In other words, Washington will develop a beatpath to
the Giants. The Beatpaths Power Rankings currently pick Washington to win,
for holding a slightly stronger position in the graph.
Beatpaths.com has more information on the Beatpaths system - it's a young site but is expanding quickly. You can find more information in our FAQ, view a demonstration of the
first few weeks of the NFL 2005 season, and find more information on how beatloops are resolved. Soon, we'll start focusing more on the NBA, and perhaps even college basketball, the most challenging of all sports for this system.
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