All You Need to Know About NFL Props (Part II of II)
by Pinnacle Sportsbook
Last week's Pinnacle Pulse, introduced some ideas about how to
gain an advantage from the increasingly popular 'Which team will
score first' prop. This week, we're sticking with the theme and
providing further hints on how to successfully price other
common props available at Pinnacle Sports.
One of my personal favorites is the proposition: 'Will the first
score be a Touchdown or FG/Safety'. As a starting point for
weighing this bet, you should look at how many TDs, FGs and
Safeties have been scored by all teams in the season to date.
Before this week's Monday night game, the frequencies of each
scoring play were as follows:
Fig 1. (up to Wk 13) 
Touchdowns 
Field Goals 
Safetys 
Frequency 
848 
546 
13 
Percent(%) 
60.3% 
38.8% 
0.9% 
This provides a good 'baseline', but
there are two adjustments to be made to refine the data for an
accurate assessment of the proposition.
First, the last two possessions of the half are more likely to
result in a field goal than at any other time in a football game
(except overtime). This bias isn't simply due to time running
out  in many cases, teams will use conservative playcalling to
ensure a field goal attempt. As a result, 50% of the time the
last score of a half is a fieldgoal.
Since close to 40% of all scores are FGs or Safeties (fig 1),
and it's been established that the final score of each half is a
FG 50% of the time, we're in a position to work out how likely
the first score is to be a FG by using simple algebra and the
average number of scores by game.
We can work out an 'average' score value using the %'s from fig
1.
(60% * 7 points/TD + 40% * 3 points/FG = 5.4 points/possession).
Historical data indicates that a 'typical' game averages a total
of 41 points, so you would expect 7.6 scores  average total
points scored/average score per scoring possession (41 / 5.4).
You'd also anticipate 3.04 FGs  average number of scores * FG
frequency % from fig 1 (7.6 * 0.4). From this we can work out
the odds (x) of a FG being scored in any scoring possession,
excluding the last score of the half.
3.04 FGs (per 7.6 scores) = 6.6 scores not at end of half * (x)
+ (1 end of half score) (0.5)
X = (3.04  0.5) / 6.6 = 0.385 (38.5%), or about +160 for a FG.
Now, you have to adjust this number for the actual matchup. For
example, take a look at next week's Monday Night matchup
between the Bears and Rams. You need to look at TDs and FGs for
each team's offense and defense for this season.
Fig 2 
Scored 
Conceded 
Team 
TD's 
FG's 
TD's 
FG's 
Bears 
34 
26 
15 
15 
Rams 
23 
27 
33 
18 
Total 
57 
53 
48 
33 
Since we do not care who scores what
(only which is scored first), we simply add the total TDs and
FGs from Fig 2  105 TD's (57+48) versus 86 FG's (53+33). 45% of
the scores involving these two teams were Field Goals, compared
to 40% for the league average. If 45% were the result of
thousands of games, you would expect that to go forward.
However, each team has only played 12 games, so expect this
percentage to 'revert to the mean'. One way to do this is to
average the two (40 + 45) / 2) which suggests 42.5% of all
scores in this matchup will result in a FG. For the first
possession, start with the baseline first possession FG score
frequency of 38.5%, and multiply by the mean FG expectancy for
these teams calculated above (42.5/40 *0.385) = 40.9%. This is
equivalent to +144, which is my price for a FG being the first
score of the game.
Once you have your novig price (+144/144), try to find a line
that is 10 cents off. If you found 'first score TD' at 134 or
better, or 'first score FG/Safety' at +154 or better, it might
warrant a play in this matchup.
There are also several ways to improve this result. You can
track safeties, or do statistical studies on scoring for many
years to plug more accurate averages into the calculations.
There are other statistical methods you can use to get even
better results. However, when you're tackling props, you want to
evaluate them without spending an inordinate amount of time as
you'll make more money by pricing 10 different props well, than
by analyzing 1 prop perfectly.
What are players betting at Pinnacle Sports this week?
Cleveland +9 129 v. Pittsburgh
We initially offered Cleveland at +9 (112). Using this unusual
number (instead of +7.5 at a normal moneyline) helps protect us
on teasers, as teasing 'large home favorites' is one of the
strongest teaser plays you can make.
The opening number of Cleveland at +9 (112) is equivalent to +8
(105) using Pinnacle's pointselling option. While the betting
public strongly favors Cleveland by a 15:1 margin, some of the
early sharps are playing Pittsburgh.
Indianapolis 1 112 v. Jacksonville
This game has remained at the current price (1 112) since
opening. Once again, teaser protection is a concern. While small
underdogs are not as dangerous as large home favorites, we would
still prefer to minimize damage from these types of plays.
Skewing the line this way is an easy way to achieve this. While
bettors favor the Colts by a 5:2 margin, the line has not moved.
The early sharps have been on both sides of the game, so it's
anyone's guess where this one is headed.
USC +1 103 v. Michigan
After UCLA stunned USC and Florida beat Arkansas, both of these
former championship contenders had to settle for the Rose Bowl.
Michigan's omission from the title game has caused controversy
over the BCS selection process and it appears that regional
politics impact who plays in the big game. Michigan was
considered the #2 team in three out of four regions, but the
South voted strongly in favor of Florida, pushing them up the
poll.
We opened the Wolverines at 2 .5 (105) but have taken twice as
many wagers on USC as Michigan, causing the line to creep down.
The sharps have mostly steered clear of this game to this point.
Florida +7 .5 109 v. Ohio State
With a convincing win over Arkansas in the SEC title game,
Florida edged out Michigan for the #2 spot in the BCS rankings
by just 1/100th of a point. The computer rankings had the two
teams tied, but Florida passed Michigan in the Harris Poll and
USA Today poll. That was just enough for Florida to earn an
invitation to the BCS National Championship Game.
We opened the Buckeyes at 7 (105), and took a lot of early
Ohio State money. The line spiked as high as 9, with twice as
many bets on Ohio State as Florida, but a few sharps played the
Gators at +8.5 and +9 forcing the line to drift back to +7.5.
