Web Science and Digital Libraries Research Group

We are halfway through the 2013 NFL season and it is time for our WSDL mid-season rankings. Both conferences have one winless team, Jacksonville in the AFC and Tampa Bay in the NFC.  The NFC is looking rather lackluster this year with no standout teams so far. The NFC East teams in particular need to get their acts together. The AFC appears to be dominating the League with  a number of teams that are performing quite well. Two teams that show up on the top of every power ranking list are the Denver Broncos and the Kansas City Chiefs. Kansas City has a great defense, using our efficiency ratings they are rated as the fifth best defense in the league. However a good defense will only get you so far when your offense is ranked at 27th out of 32. Denver on the other hand has the highest ranked offense in our system with a lot of that on Peyton Mannings shoulders. A good passing offense correlates quite well with a team that wins games. Here is where our ranking system rates e...

The NFL Playoffs are only a few weeks away. With the end of the regular season in sight there are a few trends that subtlety change the game. One of the trends is the weather. Tennessee is playing at Green Bay and snow is in the forecast. Another end of the season trend is displayed by teams that have clinched playoff positions. They rest their starting lineup and play backup players. That is more of a week 17 phenomenon but with Atlanta and Houston both at 12-2 for the season they may play some non-starters during the game. This ranking system is based on team performance and does not take trends like the weather into account. Our ranking system is based on Google's PageRank algorithm.It is explained in some detail in past posts . A directed graph is created to represent the current years season. Each team is represented by a node in the graph. For every game played a directed edge is created from the loser pointing to the winner and it is weighted by the Margin of Victo...

Recently I was emailing a friend and wanted to update her about the recent buzz we have enjoyed with Hany SalahEldeen 's TPDL 2012 paper about the loss rate of resources shared over Twitter.  I remembered that an article in the MIT Technology Review from the Physics arXiv blog started the whole wave of popular press (e.g., MIT Technology Review , BBC , The Atlantic , Spiegel ).  To help convey the amount of social media sharing of these stories, I was sending links to the sites using social media search engine Topsy .  Having recently discovered it, Topsy has quickly become one of my favorite sites.  It does many things, but the part I enjoy most is the ability to prepend " http://topsy.com/ " to a URI to discover how many times a URI has been shared and who is sharing it.  For example: http://www.bbc.com/future/story/20120927-the-decaying-web becomes: http://topsy.com/http://www.bbc.com/future/story/20120927-the-decaying-web and you can see all the...

After running the R script for the week 8 rankings, the first thing that struck my mind was the disparity in the size of the nodes between the AFC on the left side of our graph and the NFC on the right side. Two weeks ago we wrote that the NFC West has been dominant so far this year. The NFC West has the best combined record and their aggregate point differential puts others to shame.  However it is not just the West division but the entire NFC conference has dominated and out-performed the AFC conference at every turn. CBS Sports rates the NFC as head and shoulders above the AFC this year. Our ranking system is based on Google's PageRank algorithm. It is explained in some detail in past posts . A directed graph is created to represent the current years season. Each team is represented by a node in the graph. For every game played a directed edge is created from the loser pointing to the winner and it is weighted by the Margin of Victory.  In the Pagerank m...

It is now five weeks into the 2012 season and the season is starting to come into focus. The topic of many online discussions is this years performance of the NFC West division compared to last year. The NFC West is one of the best performing divisions so far this year, which is a far cry from last year. They are certainly doing well in our ranking system. Our ranking system is based on Google's PageRank algorithm.It is explained in some detail in past posts . A directed graph is created to represent the current years season. Each team is represented by a node in the graph. For every game played a directed edge is created from the loser pointing to the winner and it is weighted by the Margin of Victory.  In the Pagerank model each link from a webpage i to webpage j causes webpage i to give some of its own Pagerank to webpage j .  This is often characterized as webpage i voting for webpage j . In our system the losing team essentially votes for the winning team with...

The NFL playoffs have arrived so grab some snacks and find a good spot to watch the games. We are going to have our own playoffs here by pitting the best performing algorithms from the regular season against each other to see which one does the best job predicting the playoffs and superbowl. While I was running the algorithms I contemplated how New England was going to perform without Welker and especially after reading that Brady has been playing with broken fingers on his throwing hand. How can my algorithms take things like this into account to improve the accuracy. Having the Colts sandbag the last few games of the regular season by benching their starters already throws a monkey wrench into the works. Then there was the Dallas-Philly game, Philadephia had the playoff spot already so did they really take it easy and let Dallas stomp all over them like that last week or are they in for another beating? I am sure Frank would say that Dallas really is that good. If their defense can...

Week 12 of the regular NFL season is over and with five more weeks to go the playoff picture is starting to take shape. The predictive algorithms we chose are coming along fine. Some are doing better than others which is to be expected. One of the algorithms we are using leverages Google's PageRank algorithm. We formed a directed graph where each vertex is one of the 32 NFL teams. A directed edge is placed for each game played with the loser pointing to the winner. The edge is then weighted with the margin of victory(mov). The mov is the winner's score - the loser's score. Then the page rank is calculated using the graph. We are using the igraph library in R to calculate the page rank. The teams are then ranked in order of page rank. This is similar to another group that has used PageRank to rank NFL teams. One of the concepts of PageRank is that good pages are pointed to by other good pages. In our case good teams will be pointed to by good teams. An interesting observ...