I can
hardly believe February is coming to an end already. Has it really
been a month since the Super Bowl already? Well, that can only mean
March Madness is just around the corner so it must be time to turn our
attention to basketball. Readers and clients frequently ask me if
there are any “key numbers” in basketball. Historically, the thinking
has always sort of been that because of the nature of scoring in
basketball that there aren’t any really important spreads. However,
some bettors have felt that 4 and 5 could be considered key so I
decided to follow up and see if there really are any key numbers in
the NBA.
First,
a little background. Key numbers are spreads (or totals) that are so
likely to fall (have the final score be that exact result) that book
managers do not like to move off them. In the NFL, there are several
key spreads with 3 (17% of final scores) and 7 (10% of outcomes) being
the major ones and 10, 4, 1, 6, 14 and 13 (4-7% each) being the minor
ones. With these numbers, book managers prefer not to change the
pointspread itself to balance action, but would instead rather change
the associated moneyline from standard odds. For example, if the
spread was –3 (at standard odds of –110 or risking $110 to win $100)
and the book had heavy action on the favorite, the line would be moved
to –3 (-115) instead of –3.5.
Why are
key numbers so bad? Simple, they increase the likelihood of a book
getting sided or ‘middled’ as a result of a line move. The easiest way
to define getting ‘sided’ or ‘middled’ is to show a quick example of
each. Remember that sportsbooks try and balance action on every game
(within reason) to minimize risk and maximize profits. Suppose the
spread opens with Bears -3. The book takes a ton of action on the
Bears and moves to –3.5 to attract money the other way. The move works
and players bet heavy on the Packers +3.5 so the wagering is equal on
both teams. Now, if the Bears kick a late Field Goal to win by 3, all
the action on the Bears –3 is pushed while the bets with the Packers
+3.5 are winners. The House loses money despite the balanced action
because it was sided (spread landed on opening or closing line).
Imagine a worse scenario, the line opened Bears –2.5 and was bet to
–3.5 where the Packers bettors finally stepped in and balanced things
up. Now if the game lands Bears by 3, the bets at –2.5 are winners as
are the bets with the Packers +3.5. Now the House has to pay both ways
(although any action at –3 or +3 is pushed) because it was middled
(spread landed between opening and closing line).
Traditional thinking on basketball has been that there are no spreads
with likely enough outcomes to warrant the same type of line move. If
you get action at –3, you move to –3.5. More action at –3.5, you move
to –4. You get the idea. However, the data for the 2001-2002 NBA
season paints a different picture since there a handful of numbers
that fall enough of the time to be considered in the same category as
minor key numbers in the NFL.
Late
last summer I analyzed the numbers for the 2001-2002 NBA regular
season in preparation for a column for a gaming magazine on
basketball. Here is a summary of the most landed on scores for the
season and their frequency:
7-points 7.4%
5-points 7.1%
6-points 6.9%
3-points 6.6%
9-points 6.4%
2-points 6.2%
8-points 5.3%
4-points 5.2%
These
eight outcomes were the margin of victory in over half of all NBA
games last year! The average margin of victory was a surprising 10.8
(boosted by a 53-point win by the T-Wolves over the Bulls in
November). This does not take into account favorites or underdogs, so
the likelihood of a spread of –7 actually landing is less than 7.4%
because the underdog would have won by 7 in some of these cases.
1-point was the difference just 3.8% of the time so if you get to see
a real buzzer beater, enjoy, as they are much rarer than most people
appreciate. Ten through 14 also saw their share of games, all coming
in 3.1-4.6% of the time. The drop-off is pretty severe after that.
Over
the last couple of weeks, I have gathered and analyzed the numbers for
this season and the results look very similar.
7-points 7.3%
5-points 7.3%
2-points 6.5%
6-points 6.4%
3-points 5.8%
8-points 5.6%
9-points 5.1%
4-points 4.3%
So far
this season, these eight outcomes account for the final margin of
victory in 48.4% of all NBA games (down slightly from 51.1%). Ten and
11 both have climbed slightly and are now 5.0 and 4.4% respectively.
One-point wins are happening 3.6% of the time. Again, above 14 the
drop-off is dramatic.
Right
now I know you are asking “So what?” Let me try and explain how this
can help you. First, you know to be very diligent in shopping for the
best line if the spread is –2 to –11. This should be the case with any
spread but is particularly important in this range. Getting –6.5
instead of –7 in the NBA is statistically more important than getting
–3.5 instead of –4 in the NFL but very, very few bettors are aware of
that fact.
Secondly, if you are going to play teasers, you now know which are the
best lines to tease. Teasing a favorite down from –7.5 to –2.5 will
cross 4 of the most likely outcomes of 7, 5, 6 and 3 so, such a line
would have to be a much better candidate for a teaser than would be a
spread of –18 or –2.
Finally, when buying points, you now can judge how valuable a half
point really is. Don’t worry so much about buying to –1. A final score
of 1 only lands in 3.6-3.8% of games, yet I see a lot of players
buying the spread all the way to –1 (and even -.5!) Buying from –3 to
–2 is a lot more valuable than is buying from –2 to –1.
Also
note that many bookmakers are picking up on this trend. Ten years ago,
you would never have seen an NBA line of –6 –115, but in today’s
competitive environment, these lines are showing up more and more.
One quick sidebar before I sign off for this week. I recently became a
father and I must say it as awe-inspiring an event as people say it
is. My athletic career never amounted to much (as my coach used to
say, “Gillespie, you aren’t very big, but you make up for it by being
slow” and that isn’t a typo…enough said). However, after I finished
packing some things into the car, I was walking back into the hospital
to pick up my son and experienced such a feeling of euphoria and
accomplishment that I now think I know how Tiger Woods felt walking
the 18th fairway at Augusta knowing the Green Jacket was his. For my
friends that are sports fans but not parents this is the best
description I can give you.
Anyways, I hope this information helps make you a better basketball
bettor. Good luck the rest of the season.
I
always welcome comments, questions and suggestions via email at
rob@bodog.com
Rob Gillespie
President
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