The app is accessed by navigating a web browser to: midsouthfencers-challengeboard.herokuapp.com/games/1
There is username and password authentication into the app (see Jen or Jeff for those credentials)
If you use the URL above, this will take you to a the MidSouth Challenge Board. The app can actually host many games, but we will be using this particular one. The way this Challenge Board is set up is that no ties are allowed (because we don't have them in fencing), and the ranking calculation is therefore different than if there are ties.
Once you're done fencing a bout, you click the Add Result button, which will open a screen with two click and drag menus. In the first menu on the left, you merely drag to select the winning fencer, who 'Defeats' the losing fencer who is selected by dragging the menu selector on the right.
If there is a fencer who's not in the current database, they can be easily added by clicking on the top menu bar Elovation, which will take you to the main home screen. If you scroll down to Players, there will be a button for 'New Player', click that, add the new fencer's name (you can leave email blank, if desired), click Create Player, and you should be done. Remember to navigate back to the correct 'game', in this case MidSouth Challenge Board
If you erroneously enter a result, (e.g. you say A defeated B, when B actually won) you can hover over that result and a delete button will show.
Click on 'Elovation' to get to the home screen; there you'll see a blue New Game button. Click on that, provide a name for the game; use the click drag selector to choose Elo (1v1 only) and unclick the 'Allow ties' check box. Why not use the Trueskill ranking method? Because it allows ties and is oriented to team play (in fact, Trueskill is a Microsoft product that they use for Xbox Live).
The nice thing about this app is that you can see a list of the most recent bouts fenced (see the image below), the current rankings of the fencers, and then a dynamically-updating chart of fencers' ranks over time. The week of 9/12/2019, from the viewpoint of the app, everyone started equally ranked and each person had a time zero score of 1000. See below for how Elo works.
This app is actually borrowed from a technology company (probably many of you have used them without knowing it, because they process credit card payments on the web) that has had a very competitive ping pong circuit. The underlying system is called Elo and has traditionally been used in chess ranking, and is used in other ranking systems like, I'd guess, Fortnite. Elo is named after a physics professor named Arpad Elo who was, no surprise, a chess player. One of the problems he identified with ratings systems that are highly dependent on numbers of wins, is that chess players could obtain higher rankings merely by beating many players who were not as good as them.
The main assumption behind Elo rankings is that people should get more credit for beating players who have higher rankings. At the same time, players with higher rankings than their opponents are expected to win and therefore get lesser credit.
The basic equation is:
Rn = R0 + K * (S - E)
Where
- Rn is a fencer's new rating after a bout
- R0 is the fencer's rating before the bout
- S is the outcome of the match (for fencing, a win = 1 and loss = 0)
- E is the expected outcome (for equally ranked fencers, this would be 0.5)
- K is a parameter to manage how much impact unexpected wins or losses affect rankings
When we started using this on 9/12/19, it assumed that everyone was equal and everyone therefore starts with 1000 points. It'll probably take a few weeks for the rankings to stabilize.