Half Point Buy - NFL Key Numbers

THE HALF POINT - TO BUY OR NOT TO BUY

THAT IS THE QUESTION

An Analysis of Key Numbersin the NFL

The concept of "KeyNumbers" in betting on pro football is nothing new. Ask anyone familiar withthe sport and they will likely know that the most common final result of an NFL gameis a three point margin. Often a tied game is decided in the final minute with agame winning field goal. Or a game that goes into Overtime is much more likely tobe decided by a field goal than by a touchdown.

How frequent does thatthree point margin occur? Between 1981 and 1998 there have been 3,942 regular seasongames played by non-Replacement players (during the 1987 Players' strike the NFLdid play three weeks of games with mostly non-roster players). Of those nearly 4,000games over 15% of them, 597, have been decided by exactly three points. That's morethan twice the number of games decided by the next most common number. 280 games,or just over 7%, have been decided by exactly 7 points. In fact, the ten most frequentnumbers account for over 60% of all final margins of victory. Here is a list of theNFL's Top Ten Victory Margins:

Margin	Occurrences	Percentage	Cumulative%
3	597	15.1%	15.1%
7	280	7.1%	22.2%
6	237	6.0%	28.2%
10	233	5.9%	34.1%
4	230	5.8%	39.9%
14	191	4.9%	44.8%
1	173	4.4%	49.2%
2	159	4.0%	53.2%
17	148	3.8%	57.0%
11	147	3.7%	60.7%

Thisinformation, while interesting, can also be useful to the handicapper and bettorbut not in the same form. The above numbers reflect the final margins but handicappersand bettors need to know the answers to a couple of very important questions. First,how often do the FAVORITES win by those margins and, second andmore importantly, when favorites win by those exact margins, how often is the pointspreadwithin a half point of those key numbers?

Let's use a simple exampleto illustrate these questions. We know that 597 times since 1981, the winning marginwas exactly three points. Of those 597 games, how often was the winner of the gamethe pointspread favorite? And more importantly, when the favored team won by exactly3 points, in how many of those games was that team favored by 2 ½, 3 or 3 ½ points?Do you see where we are headed?

As handicappers we lookto find games that present the best opportunities for success in covering the pointspread.Whether we use statistical analysis, situational evaluations, trends, emotions, coaching,historical rivalries or any other factors we deem important in the selection of whichgames to play, we ultimately select those games that we believe have the highestprobability of covering the number.

As bettors we are facedwith a different decision-making process. Once we have decided on the teams we wishto play, we now must find the most favorable price. Shopping around for the bestline is perhaps even more important than the team we decide to play. Look back uponyour experiences over the years and you will recall on more than just a few occasionsthe number of times you lost a game by that smallest of margins, a half point. Orthe number of times you've said to yourself "Boy, am I glad I got that extrahalf point. It turned a push into a winner (or a loser into a push).

The point here is (pardonthe pun) that selecting the likely pointspread winner in a game is only one phaseof the process. Getting the best price is just as, if not more, important.

Here in Las Vegas it isnot unusual to see lines on the same game fluctuate by as much as a point or a pointand a half on many college games, and often there are half point fluctuations onseveral pro games. Unfortunately as the Sports Book and Casino industries consolidate,there are a fewer number of unaffiliated betting lines available. But there are enoughso that at any given time different numbers are available on the same game.

Fortunately, other optionsare available and one option often misunderstood is the option to 'buy' an extrahalf point on a game, laying an extra 10% vigorish for the privilege. In other words,instead of laying 11 to 10 on a team at - 6 ½, you have the option to lay 12 to 10(6-5) and 'buy' that line down from - 6 ½ to - 6. Underdog player have the optionto buy the line up to + 7. The question we wish to explore is whether buying thatextra half point is a good option and, if so, under what conditions. This is wherethe 'key number' information presented earlier comes into play.

We saw that there are justten numbers that account for over 60% of all final margins. One could easily concludethat whenever we have the opportunity to but an extra half point onto or off of oneof those 'key' numbers that it should be done. That is not necessarily so. Lookingat the frequency, for example, with which the number '3' falls, it is easy to beimpressed with the fact that almost one game in seven, 15%, lands on that number.But the questions raised earlier was, 'How often does the FAVORITE win by exactly3 points?' But even that is not the proper question to ask in determining whetherto buy that additional half point. The correct question is "How often does afavorite of 2 ½, 3 or 3 ½ points win the game by exactly 3 points?" In that waywe can determine whether or not buying the extra half point onto or off of the number3 makes sense. Similar questions must be asked about those other 'key numbers' aswell.

Here's what we mean. Theonly time that the key number of 3 is of interest to us is when buying an extra halfpoint enables us to turn a loss into a push or a push into a win. If a 3 point favoritewins by 7 points it is of no consequence to us. The additional half point did notcome into play. Whether you laid -3 or bought the half point to lay - 2 ½ did notmatter -- you won anyway. Similarly if you played the underdog and bought the halfpoint from + 3 to + 3 ½ you lost anyway when the Favorite won by 7 points. But thereinlies the key to the proper analysis of this issue.

How often does a half pointmatter overall? Let's answer the question this way. Since 1980 there have been 90games that ended in pushes and another 145 games that fell a half point away fromthe pointspread. That represents 5.6% of all games played during the past 19 seasons.Obviously many pointspread numbers are involved in that 5.6%, not just the key numbers.But let's delve a little further into this issue and look at how often that extrahalf point has mattered at various pointspread levels..

Here are some statisticsthat better allow us to determine whether or not we should buy that half point. Thedata is from the over 3700 games played between 1982 and 1998 and is reliable. Thelines used in the following chart are the Closing Lines from the Stardust Race &Sports Book in Las Vegas.

This chart reveals some very interesting and useful information.First, here's how to read the chart, which is divided into two parts. The first partof the chart looks at buying a half point from the perspective of a Favorite. Let'suse the case of a 6 point Favorite. The chart shows that there have been 180 timeswhen the Closing Line was 6. A Favorite bettor wants to see what happens if he hadbought a half point and laid - 5 ½ instead of - 6. The results of those 180 instancesare as follows. The 6 point Favorite won by 5 points or less, or lost outright, 82times, thus still resulting in a losing wager in which the half point did not matter(the 'Still A Loss' column). The 6 point Favorite won by more than 6 points 93 times('Still A Win" column), again not impacting the pointspread result from havingbought the half point. Since the move from - 6 to - 5 ½ cannot result in a 'push'the "Loss to Push" column is zero. However, there were 5 instances in whichthe 6 point Favorite won by exactly 6 points, thereby making the decision to buythe half point from - 6 to - 5 ½ a good one - it turned what would have been a pushinto a win (the "Push to Win" column).

That's the first part ofthe analysis. Now we must examine the effect of buying the half point. We shall usea standard wager of laying $110 to win $100. When you buy the half point you lay6-5, or $120 to win $100. The 'cost' of buying that half point is $10 per wager andobviously will not affect your bottom line on winning wagers but will increase yourlosses on wagers you lose. In our example of the 6 point Favorite we see that ofthe 180 times the line was -6, the Favorite won by more than 6 points 93 times whichresults in no impact. We'd lay the 6-5 and have it returned to us with our winningin those 93 instances. However, there were 82 instances in which the wager lost atboth -6 and - 5 ½, costing us an additional $820 by laying the added vigorish. Onthe other hand, there were 5 situations in which a game that otherwise would havebeen a push was turned into a win by laying just 5 ½, netting us an additional $500.The net effect, however, was that buying the extra half point from - 6 to - 5 ½ resultedin an added loss of $320 (the $820 in added losses less the $500 added winning fromthe pushes turned winners).

The second half of thechart looks at buying the half point from the perspective of an Underdog player.In this case a line of + 6 would be bought up to a + 6 ½ and a similar analysis hasbeen done.

We've concentrated ouranalysis on lines ranging from 1 to 10 ½ which includes almost 90% of all games playedover the past 17 seasons. Most of the 'Key Numbers' referred to at the start of thisarticle are included in the charts.

Notice that buying froma whole number to a half point number (i.e. from 7 to 6 ½) cannot result in a pushso the purchase can only change a push into a win or a loss. Buying from a half pointnumber onto a whole number (i.e. from + 4 ½ to + 5) cannot turn what would be a pushinto a win or a loss but can result in turning a win or a loss into a push.

Now the good news/bad news.The good news is that there are several pointspreads at which buying the extra halfpoint has proven to be profitable over the years, albeit marginally in some cases.Buying Underdogs up from + 2 ½ to + 3, + 3 to + 3 ½ and + 9 ½ to + 10 have all resultedin profits. Likewise, buying Favorites down from - 2 ½ to -2, - 3 to - 2 ½, - 3 ½ to-3 and - 10 ½ to -10 have all resulted in bettering the bottom line.

Unfortunately most SportsBooks in Las Vegas do not permit the buying onto or off of a '3'. The Books knowthe importance of this very key number and realize the potential for both Favoriteand Underdog players to profit from this number. If you can find a place that willpermit you to buy from - 3 to - 2 ½ or from - 3 ½ to - 3 you should take advantage.Buying from + 2 ½ to + 3 and from + 3 to + 3 ½ is also advised whenever possible. Yeteven with the prohibition of buying onto or off of 3 there are still those otherinstances that have been profitable and are permitted. A secondary source of goodnews is the revelation that buying a half point in what might seem to be other obvioussituations (such as with the numbers 6 or 7) is not justified by historical resultsand should be avoided even though many people will mistakenly believe that thosenumbers are just as important as is the number '3'.

By now you can appreciatethat picking the pointspread winner of a game is not enough. It is certainly veryimportant but knowing how to play your selection is just as important, especiallywhen the pointspread involves some of the key numbers in the NFL. These opportunitiesmay occur just a few times each season but proper understanding and use of the keynumber concepts can increase your overall winning percentage and, more importantly,your overall profits.

Good luck during the remainderof the season.