Thursday, October 9, 2014

Rushing Success Rates - Week 15

[If you're not familiar with success rates, please see the original post here.]

Running Backs

Minimum 30 carries.


Minimum 10 attempts

Friday, September 19, 2014

Playoff Outlook - Week 13

It's week 13, every team has played every other team, and for some teams, there are only 6 games left on the schedule.  Time to take a look at the playoff picture.

The Wild West

BC Lions
Current Record: 7-4
Games Remaining: 7
Opponent Win Percentage: 0.539 (5th hardest, easiest in West)
Road Games: 4
Division Games: 4

The bad news for the Lions is they drew one of the short straws this year, and have to face the Stampeders 2 more times this season.  The good news is that the remaining 5 games come against teams with a combined record of 21-33, which would rank as the 3rd easiest opponent schedule. They currently sit in 4th position, but a strong finish and a road win in Edmonton could get them the 2nd seed.

Key games: Week 19 @ EDM
Projected finish: 10-8 (3-4), 3rd in West

Calgary Stampeders
Current Record: 10-1
Games Remaining: 7
Opponent Win Percentage: 0.570 (3rd hardest in league, 3rd easiest in West)
Road Games: 4
Division Games: 6

Can anyone beat the Stamps?  With Bo Levi Mitchell done for a least the immediate future, the task looks a little less daunting, but with Drew Tate under center the Calgary quarterbacking situation isn't exactly hurting.  The Stampeders have more West Division opponents on the schedule than any other team, but they are in the driver's seat with 7 games to go and no obvious losses on the horizon.  Even if they go 0-3 on the road vs division rivals, a playoff bye as the #1 seed looks all but wrapped up.

Key game(s): Week 14 vs BC, Week 20 @ BC.
Projected finish: 15-3 (5-2), 1st in the West.

Edmonton Eskimos
Current Record: 8-3
Games Remaining: 7
Opponent Win Percentage: 0.558 (4th hardest in league, 2nd easiest in West)
Road Games: 4
Division Games: 5

The Eskimos are undefeated this year, if you don't count games against those pesky Stampeders. Fortunately for Edmonton, they won't face Calgary again unless it's in the playoffs. With 3 games against the quarterback-less Riders on the schedule, and a game in hand against BC, the Eskimos are have the second seed in their sights, but they will probably need another win against BC and at least 2 of 3 against the Riders.

Key game(s): Week 14 vs SSK, Week 17 @ SSK, Week 19 vs BC
Projected finish: 13-5 (5-2), 2nd in West

Saskatchewan Roughriders
Current Record: 8-3
Games Remaining: 7
Opponent Win Percentage: 0.632 (hardest in league)
Road Games: 3
Division Games: 5

The Riders sit in 3rd place currently (Edmonton holds the tie-breaker on points at the moment), but they need to find a quarterback in a hurry or they'll quickly find themselves on the outside looking in. Three games against a strong Edmonton team loom on the horizon, but two are at home, and a strong showing can propel them to a home playoff game in the West semis.  The good news is that a season sweep of the Bombers gives them the 4th place tie-break if necessary, in a year where a possible cross-over looks appealing.

Key game(s): Week 14 @ EDM, Week 17 vs EDM, Week 20 vs EDM
Projected finish: 9-9 (1-6), 4th in West (cross-over)

Winnipeg Blue Bombers
Current Record: 6-6
Games Remaining: 6
Opponent Win Percentage: 0.609 (2nd hardest in West)
Road Games: 3
Division Games: 4

Three losses to the arch-rival Roughriders has crushed what looked like a very promising season for a surprising Blue Bomber team.  With the second hardest schedule in the West and the fewest games remaining, the Bombers need some help from the teams they are chasing.  While they can't win a tie-break with the Riders, wins against BC and Edmonton would still give them a chance.

Key game(s): Week 16 @ EDM, Week 18 vs BC
Projected finish: 9-9 (3-3), 5th in West

The Erratic East

Hamilton Tiger-Cats
Current Record: 3-7
Games Remaining: 8
Opponent Win Percentage: 0.368 (easiest in league)
Road Games: 4
Division Games: 5

Finally, the Eastern teams get to play each other and this ugly win-loss discrepancy with the West will start to even out.  The Tiger-Cats currently sit in the 1st seed in the East, and are looking at the easiest schedule in the league down the stretch.  The Argos are just below them though, and face the 2nd easiest, so their head to head matchups will likely determine the outcome of the East.

Key game(s): Week 16 @ TOR, Week 18 @ TOR
Projected finish: 6-12 (3-5), 2nd in East

Toronto Argonauts
Current Record: 3-8
Games Remaining: 7
Opponent Win Percentage: 0.378 (2nd easiest in league, 2nd easiest in East)
Road Games: 2
Division Games: 5

Toronto has the second easiest schedule down the stretch, and the fewest road games of any team. If Owens and the rest of the receiving corps can stay healthy for Ricky Ray, Toronto looks to be the team to beat in the East.

Key game(s): Week 16 vs HAM, Week 17 vs MTL, Week 18 vs HAM
Projected finish: 8-10 (5-2), 1st in East

Ottawa RedBlacks
Current Record: 1-9
Games Remaining: 8
Opponent Win Percentage: 0.414 (4th easiest in league, hardest in East)
Road Games: 3
Division Games: 5

The Expansion Blues are no joke, as Ottawa fans are finding out, and with the most difficult schedule in the East ahead, it doesn't look good for the Lumberjacks.  Wins against their Quebecois neighbours give them a real shot at 3rd place, but in a down year for the East, that doesn't look like it will be enough for a playoff spot.  The RedBlacks need at least 5 wins to have a shot, and to win a tie breaker with Hamilton they'll need to win both matchups.  It's must-win from here on out.

Key game(s): Week 14 vs MTL, Week 15 @ HAM, Week 18 vs MTL, Week 19 vs HAM.
Projected finish: 3-15 (2-6), last in East

Montreal Alouettes
Current Record: 3-8
Games Remaining: 7
Opponent Win Percentage: 0.392 (3rd easiest in league, 2nd hardest in East)
Road Games: 4
Division Games: 5

With 2 wins in their last 3, and one against Hamilton, the Alouettes have a good chance at keeping their playoff streak alive, but only if they can keep up their success against division rivals.  Four road games will make that a tall order, but with a game in hand against Hamilton, a week 20 matchup on the road may decide the 2nd seed in the East and what appears to be the last spot in the playoffs.

Key game(s): Week 17 @ TOR, Week 19 vs TOR, Week 20 @ HAM
Projected finish: 5-13 (2-5), 3rd in East (eliminated due to West cross-over)

Filling in the blanks for TSN's Field position article

On September 18th, Paul LaPolice wrote this great article for TSN, which breaks down some of the scoring data across the CFL this year.  It's a good read, if you haven't checked it out yet, take a moment and do so, I'll wait here.

The one downside to this article was that Mr. LaPolice opted to trim his tables down to highlight only a subset of teams in each table.

Using the Drive Search feature on, I will fill in the rest for those who are interested. Please note that because I do not have direct access to the stats that TSN uses, my numbers are slightly different. I can't explain these discrepancies, as I'm confident in the accuracy of my data.  It's possible that in some cases, our criteria for certain cases is different, for example the total number of possessions (TSN cites 1497 possessions, while my data includes 1485.)  Whatever the reason for these discrepancies, they constitute a very small portion of the data and do not change the overall trends of the results.

For each of these datasets, if you click the link to the underlying search, you'll be able to view the stats from the defensive perspective (which team allows the highest TD percentage, etc), as well as each individual drive that matched the results.

Touchdown Percentage

Tm G Possessions TD Pct
CGY 11 163 34 21%
WPG 12 178 25 14%
EDM 11 171 23 13%
TOR 11 173 23 13%
SSK 11 161 19 12%
BC 11 169 19 11%
HAM 10 156 17 11%
MTL 11 169 13 8%
ORB 10 145 11 8%
Total 98 1485 184 12%

Drives starting inside your own 20 yard line

There is a slight semantic difference in the search here - "inside the 20" on the drive finder includes the 20 yard line, while the TSN data does not.  The actual search results presented here from is "Drives inside own 19".  That said, the TSN article may mixing the two data sets, as they claim a 21% TD rate for the Stamps, which is correct if I include the 20 yard line, but a 0% rate for the Riders, which is only correct if I omit the 20 yard line.  The issue here may be that TSN's source tracks the starting line of scrimmage independently from the CFL's scoring, which is what's stats are based off of.

Tm G Possessions TDs Pct
CGY 10 32 6 19%
MTL 10 21 3 14%
WPG 11 30 4 13%
BC 10 21 2 10%
ORB 9 20 2 10%
TOR 11 33 3 9%
EDM 10 24 2 8%
HAM 9 29 1 3%
SSK 10 25 0 0%
Total 90 235 23 10%

Drives starting from own 21-49

I don't have a good search for this one, I had to search for drives within own 49 and remove the data from drives within own 20.  Even still, my numbers are quite different from TSN's here.

Tm G #Dr TDs Pct
BC 11 118 11 9%
CGY 11 86 16 19%
EDM 11 112 11 10%
HAM 10 95 12 13%
MTL 11 124 6 5%
ORB 10 105 6 6%
SSK 11 104 6 6%
TOR 11 110 10 9%
WPG 12 110 16 15%
Total 98 964 94 10%

Starting from Opponent's End

I'd very much like to see TSN's source data on this one to compare, because they or I have a big error (or Mr. LaPolice made a mistake in this section).  There are minor discrepancies here such as the article crediting the Riders with 9 touchdowns on 21 possessions, vs my data showing 8 touchdowns on 21 possessions, but the big one here is Toronto, which isn't included in the article's data.  The article claims that the Riders lead the league with a 43% TD rate, but according to my data, Toronto is way ahead of the pack at 53%.

Tm G #Dr TD Pct
BC 11 21 5 24%
CGY 9 30 12 40%
EDM 9 26 9 35%
HAM 9 20 3 15%
MTL 8 15 2 13%
ORB 7 10 2 20%
SSK 8 21 8 38%
TOR 9 17 9 53%
WPG 11 25 5 20%
Total 81 185 55 30%

Monday, July 28, 2014

Who are the CFL's most successful runners?

Anyone who's watched a football game can tell you that not all yards are created equally.  QBs pile up yardage in failed comeback attempts, and running backs rack up the carries while teams protect a lead.  They might look the same on the score sheet at the end of the day, but there is a significant difference between an 8 yard gain on 2nd and 5, and an 8 yard gain on 2nd and 15.

Success Rate

Success rate is a simple metric that attempts to put a number on the difference between those plays - one of those plays is a successful one (it gained a first down), the other is not.

Your definition of success may differ from mine, but I've opted to define a successful running play as follows:

1) On first down, it gained at least 50% of the needed yards.
2) On second or third down, it gained 100% of the needed yards.
3) The runner did not fumble on the play.

In other words, a 5 yards on 1st and 10 is successful, but 5 yards on 2nd and 10 is not, and neither is a 15 yard run on 1st and 10 where the runner fumbled after gaining the yardage.  Possession of the fumble is not relevant, any fumble, recovered by the offense or not, is considered to be an unsuccessful play.  (Ask any coach and I think you'd find they agree.)

Success rate is shown as a percentage (successes / total attempts).  A rusher with a high yardage total and low success rate probably tends to have long runs mixed with frequent stops for short or no yardage.  A rusher with a low yardage total and high success rate is getting just enough to be successful, and not much more (perhaps indicative of a goal line QB or full back).

2014 Success Rates through Week 5

Through week 5 I've limited this list to running backs with at least 15 carries, and quarterbacks to those with at least 5 carries.  I will increase these value as the season goes on.
Success Rate - Running Backs (min 15 attempts)

Success Rate - Quarterbacks (min 5 attempts)
By itself, Success Rate doesn't tell the whole story about a runner (would anyone rather have Pat White's 100% success rate and 1.7 YPC than Tanner Marsh's 88% and 6.4 YPC?), but it does provide an interesting metric to add to the conversation.

2013 Success Rates

I intend to put up a page on to display success rates for all seasons, but in the meantime, here are the values for last year.
Success Rate - Running Backs (minimum 50 attempts)

Success Rate - Quarterbacks (minimum 15 attempts)

Friday, July 25, 2014

Missing data status

At launch, data from 2009, 2010 and 2013 was available for the majority of games. All game boxscores for these years are in the system, but a small number are missing play data. Data for games in 2011 and 2012 is available, but has not yet been processed. 2014 data is being entered into the system on a weekly basis and will be kept up to date throughout the season. Data for 2011 is currently being processed as time allows, and 2012 data will follow. As games are completed they will become immediately available on the website. There is no time frame for completion, but I hope very much to have them ready before the start of the 2015 season. There is currently no work being done on games with missing play data, these games will remain flagged in the system (a note appears at the top of these games), and individual play data will remain unavailable until the back log of 2011 and 2012 games has been completed. This page will be updated as the status changes.

A deeper look at the Edmonton fake punt (July 24, 2014)

Some background: Expected Points and Expected Points Added

Expected points (EP), and more specifically, Expected Points Added (EPA), are metrics I use on that has been used by NFL analyst Brian Burke for quite a few years now.

Using historical scoring data, we can assign a point value for every down/distance/line of scrimmage combination in a game.  By looking at every play and then the next score for either team, then grouping it by down/distance/LOS, we can come up with an average expectation for that play.  EP can be positive or negative, indicating whether we expect the offense (positive) or defense (negative) to score next.  In calculating the values, some game situations are filtered out in order to keep the values more accurate; plays which occur in the last 4 minutes of a half, or when the score margin is 14 points or more are not included in the calculations, in order to decrease the effect of garbage time or 2 minute drill type possessions.

Once we have a value for each game situation, we can then calculate EPA, which is simply the difference between EP on the next play and EP on the current play (EP After - EP Before). Positive EPA means the play moved the offence into a better position, negative means they are worse off than before.

Looking at EPA and comparing some possible outcomes can give us clues to whether in-game decisions were good or bad, or if risks were worth it.

The Play

On 3rd and 10 from their own 6 yard line with 26 seconds to go, Edmonton opted for a fake punt and gained just shy of the 10 yards necessary for the first down.  Calgary scored a touchdown on the next play, and Edmonton was left looking like they'd made a bad decision.

But was it really a bad decision?

Outcomes and potential EPA

3rd and 10 from your own 6 yard line is a bad place to be, and the EP value reflects that.  EP in this position is -1.3 points for the offense, meaning most of the time, the offense will give up the ball (or a safety) and the defense will be the next team to score.

Going into the play, they had three options: 

1) Punt - Edmonton averaged 38.7 net punt yards on the night, so punting from the 6 yard line would expect to give Calgary the ball back somewhere around the 44 yard line.  1st and 10 from their own 44 yard line carries an EP of -2.4 for the Edmonton defense.  Over the past 5 years, kickers have averaged 81% on field goal attempts from this range, which was the mostly likely scenario given the time remaining in the quarter.  EPA for this outcome would be -2.4 - -1.3 = -1.1

2) Go for it (and succeed) - Lets assume they got those extra needed inches, and kept the ball on their own 16 yard line.  That gives Edmonton 1st and 10, which carries an EP of 0.3.  In this situation though, Edmonton would certainly have opted to kneel out the quarter, so in actuality their EP for this case would be a flat 0 EP.  EPA for this outcome would be 0 - -1.3 = 1.3

3) Go for it (and fail) - Or exactly what happened, in other words. On average, teams on 3rd and 10 that go for it are successful 23% of the time, for an average gain of 6.3 yards.  Plugging in the average yardage gives Calgary back the ball on the Edmonton 12 yard line, for an EP of -4.0.  EPA for this outcome would be -4.0 - -1.3 = -2.7

The success rate for 2 and 3 are linked, meaning the true value of going for it must be calculated as a fraction of both, however.  Historically, teams have converted on 3rd and 10 just under 23% of the time, which includes fake punts.  That means the average EPA is a combination of the two:
EP_Success * SuccessRate + EP_Failure * FailureRate
For this situation, we get an average EPA of -1.78

To recap, that leaves us two outcomes - punt for an EPA of -1.1, or go for it, for an EPA of -1.78.  Those are surprisingly close.


In a vacuum, or as a standard third down gamble, going for it here is the wrong decision.  Both options are bad, as both indicate that Calgary is more likely to score next, but going for it is a little more than a half a point worse over all.

But, this didn't happen in a vacuum, time was a major factor here.  Ordinarily, gaining your team a first down on your own 16 yard line isn't worth all that much, especially when it comes at the risk of a -4.0 EPA swing.  But in this case, gaining the yardage would have allowed Edmonton to kneel out the quarter, giving up zero points, opposed to giving Calgary the ball back in position to kick a field goal from a spot on the field where kickers are fairly successful (81%).

And it wasn't a gamble, it was a fake punt.  Fake punts are a bit harder to quantify the success rate on, as they rely heavily on the element of surprise, and whether or not the team has found a weakness they hope to exploit.  I don't know the league average for success on fake punts, but I would wager that they are slightly more likely to succeed than a 3rd and long gamble, especially if the punting team has spotted something they think they can exploit.  Edmonton only needed to convert at a 40% rate in order to break even vs the punt.

It's a very close call on this one.  In a tie game, giving up the ball and a likely field goal could have been the difference in the game.  Conversely, giving up the ball inside your own 20 is a huge risk, but with less than 20 seconds left, there's a very good chance that most of the time, Calgary only walks away with a field goal here anyway.  

So should Edmonton have punted? I actually like the decision here: if the Edmonton coaches felt that the Calgary defense was unprepared or likely to cheat back to block, they may have felt their chances of succeeding were much higher than 40%, and after a good defensive half, they had to feel that they could hold Calgary to a short field goal in the case of a turnover.  Unfortunately, Edmonton's defense didn't hold, and the gamble resulted in the worst possible outcome, but I give credit to Chris Jones and his staff for making the aggressive choice at a reasonable time.

Thursday, July 24, 2014

July 24th Update has been updated with a few minor enhancements:

1) Player and team pages now include "pass targets" (times a player made a catch or was targeted with a pass).  This data was always tracked, but for some reason not available on any pages.

2) Added a list of recent games to the front page for quicker access.

In addition, I've greatly improved the way that game day rosters are handled.  Going forward, the official game day roster will be used to determine which players were actually in the game, so the per game stats and player game logs should be much more accurate.  (Previously I used the transaction list to try and guess which players were available, but the transaction list is incomplete and results in some players appearing to still be on a team, when in fact they were inactive or even no longer on the roster.)  It will take some time to implement this into the games in the archive, but it will be done eventually.