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LINE-UP PERFORMANCE ANALYSIS
AND PREDICTION
The English Alphabet is well known to all the
civilized world and therefore most of the people of this
planet are familiar with it.
It consists of 26 letters, out of which, we can make words,
which have various meanings. I’m pretty sure, all of you are
familiar with this, and if not, you should consider going back
to school! |
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| Let’s pick up 12 random letters out of the
alphabet. It can be any twelve, and let’s try to make some
5-letter WORDS. |
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| Here, we already have created six words and
possibly there are many more. |
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However, it is obvious that some combinations
of letters make words with meaning and some don’t, like these,
which make no sense at all.
Probably or certainly this group is larger, that means there
are more combinations of letters, which don’t make sense at
all! |
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The question is: How many combinations of
letters is it possible to have?
In other words: If one has 12 letters and wants to create
5-letter words, how many of those can one build? |
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Let’s look at a simple example.
Out of the 4 letters A,B,C, D we can make 6 combinations of
two-letter “words”:
AB, AC, AD, BC, BD, and CD. |
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| Now, if we are also interested in the position
of the letters, then, we have not only AB but also BA, that
makes 2 permutations, in each, and finally we end up with 12
permutations. |
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What I mean by this is that a word can be an
anagram of another.
In other words, we can make in this sense, not only STEAM but
also TEAMS, not only TRAIN but also INTRA and, in both cases,
the words have totally different meanings. |
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| Mathematics can help us here to calculate the
total number of combinations, |
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| and if we take permutations into account, i.e.
if we change the position of the letters, then the total
number is a lot larger. |
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| I know these mathematics are “all greek to
you” but from our first example of 12 letters with 5-letter
words, the total number of resulting combinations is 792, |
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and since I would like you to believe me, this
number comes out of all these simple multiplications.
I know you are sports / basketball people but what does this
have to do with you? |
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Think that the coach has a roster of 20-26
players, like the letters of the alphabet, selects 12 for each
game and uses 5 at a time.
Well, according to maths, he has to choose one combination of
5 players out of 792 possible ones, each time he decides to
make a substitution. |
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Like the alphabet, some make sense, some
don’t, some are good, some are bad, and this can be the case
if we use anagrams.
The equivalent in basketball is moving, for example, the “play
maker” to position “5”, or the “center” to position “1”, what
we call permutation in mathematics. |
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The coach knows very well, without even giving
it a try that some combinations are totally out of question.
So, before the game he prepares some line-ups, but during the
game he tries some line-ups, perhaps by accident (for example,
if a player has to come out with 5 fouls or injury). |
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Let’s see that mechanism.
During the game the coach asks a player to come out and
another to come in.
Later on, the same happens. So, gradually, during the game, he
makes a lot of substitutions. |
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Thus, a number of questions arise.
First of all:
How many substitutions the coach makes. |
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| Second: How many times does the same line-up
appear on court. |
| Third: How many different line-ups
(combinations) appear on court. |
And of course, which line-up is best.
We studied line-up performance very carefully and in 1995
during Eurobasket we applied it for the first time. |
To go back to the triplet 26-12-5 we can
assume that a coach has most of the times a roster of 20-26
players.
For a match he has to select 12 and on court he has to choose
5 at a time.
We will look at the roster of AEK, the champion and leader of
this year’s regular season. |
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| AEK will serve as an example for this
presentation not only for the impressive season 2001 - 2002 they had, but
also because coach Dragan Sakota, belongs to this group of
professionals with high intuition for fundamental coaching,
like, Ioannidis,Alexandris,Petropoulos, Subotic, Ivkovic,
Obradovic, Serf and A1 rookies Yannakis, Pilafidis |
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Let’s concentrate on the game AEK –
Panathinaikos 86-62, a victory of AEK.
Sakota selected these 12 players for the game of Day 7. |
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These 5 players are the starting line-up. Of
course, according to what we proved previously this is one
line-up out of the 792 possible ones.
Holden, Zissis, Dikoudis, Betts and Kakiouzis are the chosen,
and as we will see later in the game did not have the best
performance. |
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First of all we have a list of all
substitutions performed by each team with all necessary
information, such as time and number of players.
Next to them, we have all statistics related to each line-up
so we can safely say that the first line-up, the starters of
AEK, did 12 points, 4 rebounds, etc. in 8 minutes with an
evaluation index of 0.19.
On the other hand, the starters of Panathinaikos did 11 points
in 6 minutes with an evaluation index of 0.33 and managed to
lead the game with one point (10-11).
Instead of going into complicated calculations for the
evaluation index, think of it, as if it were something like
scoring per minute, but don’t forget the winner has always
better tendex than the loser..
This means that if each line-up makes a score of one point
difference and the coach makes 20 substitutions the game will
end up with 20 points difference.
So, actually, we are trying to calculate the contribution of
each line-up to the final score.
Anyway, in this game, Sakota used two line-ups in the first
quarter by substituting Mihalis Kakiouzis with Arian Komazec
at 01:44, improving his team’s performance impressively. |
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These graphs display performance of each team
during the game.
They show the tendex of each line-up, but, as I said before,
think of scoring, or points per minute.
If a line-up scores 2 points per minute, it is better than
another, which scores 1.5.
Ideally, every time the coach makes a substitution, he must
bring on the court a better line-up, so this diagram does not
have ups and downs but only ups.
The situation is similar to a group of 5 workers who build a
wall: the wall of difference of two scores. If a substitution
is not successful the next workers destroy the wall, which is
inherited to them.
And of course, if the substitution is successful then workers
carry on building, increasing the difference.
In any case, Sakota used 15 “teams” during the game and he
repeated the same line-up only once (end of 3rd quarter –
start of 4th), whereas Obradovic used 18 “teams”, three of
which were repetitions. |
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We examined for many years all these in the
course of a whole championship of 26 days and we came to
various conclusions.
For these conclusions, we used all line-ups, that is, all
combinations of players used by the coaches, with their total
time, total statistics and performance. |
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Before the change of the 30” rule a “healthy”
team used around 100 line-up combinations during the year, a
coach without players, i.e. without choices used around 70,
and a coach who had not been able to decide on certain schemes
had to try 130 or even more.
Today, these numbers are 110, 150, 180. |
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Let us look at the top 10 line-ups,
combinations, of AEK, sorted by their total time of play.
First of all, Sakota does not depend on one line-up. We can
see that the three first line-ups have played more or less
equal time during the year. |
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| The best performance belongs to the first
selection that means that the nose of the coach is good and if
we look at a game-by-game analysis we realize that its
performance is very stable, thus the average of 0.580 has been
like this in most of the games. |
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On the contrary, the fourth line-up, which we
examined previously, and has an overall index of 0.444, has
been unstable, which is the case because of the strength of
the opponents.
This means that in some games the opponent is easy to beat, in
some the opponent is strong. |
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A week before the start of the game, the coach
is equipped with all this information and of course with all
the corresponding data for the opponent.
He can check his good line-ups and select the stable ones in
parallel to video analysis, which is offered along with the
time codes shown in the previous slide. |
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Using a stable line-up, the coach can be sure
of the expected performance.
At the same time, from the lists he can have an estimate of
the opponent’s expected performance and he can act
accordingly.
The question is: How long does it take to realize all these
after each substitution? |
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The mechanism is like in elections, where you
have the previous results and using a sample of 10% from the
current data you estimate the new result.
The only difference, of course here, is that you can alter the
result by making a substitution to improve your team’s
performance. |
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Of course, the coach needs a good supporting
team, which, during the game, compares the lists, looks at the
monitors, in order to follow the current performances.
All these should be performed in parallel to the traditional
activities of the assistant coaches. |
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