Kaleidoscope Series Lesson #6
MatchPoints versus IMPs
-----------------------
The difference between MatchPoints and IMPs is
simple enough. In MatchPoints, your score is put on
a list with everyone else's score. You get one
MatchPoint for every person you beat on this list, a
half a MatchPoint for everyone you TIE on that list.
Hence, if you do better than the 12 other people who
played the hand, you would get 12 MatchPoints. An
average result would be 6 Matchpoints (i.e. "MPs")
if 13 pairs play the hand. If you were to beat
2 pairs and tie 3 others, you would get 3-and-a-half
Matchpoints: 2 for the two you exceeded, a half
each for the three that you equalled.
On OKBridge, this is simply converted to a
percentage with 100% going to anyone who beats all
of the other pairs, 0% to anyone who registers the
worst score. In mathematical terms, we are merely
converting a percentile into a percentage.
In International Match Points ("IMPs"), we
take the DIFFERENCE between the scores that you
and your opponents have achieved and convert that
difference to an arbitrary number of "IMPs"
according to this scale:
Difference in Raw Scores IMPs
0-10 0
20-40 1
50-80 2
90-120 3
130-160 4
170-210 5
220-260 6
270-310 7
320-360 8
370-420 9
430-490 10
500-590 11
600-740 12
750-890 13
900-1090 14
1100-1290 15
1300-1490 16
1500-1740 17
1750-1990 18
2000-2240 19
2250-2490 20
2500-2990 21
3000-3490 22
3500-3990 23
4000+ 24
On OKBridge, seeing percentages on the scoreboard
is a sign that we are playing MatchPoints. If decimals,
the game is IMPs.
----- Quiz #1 -----
1. Drew "CANOOZ" Cannell, upon returning to compare scores
with his team mates, announced that on Board #1 they
would "lose 'em all". How many IMPs did he mean?
2. At which form of the game are there more likely to be
"pushes", resulting in no score for either pair? IMPs
or Matchpoints?
3. At which form of the game is a "dark horse" more liable
to stage an upset win? IMPs or Matchpoints?
----- MPs versus IMPs and IMP Pairs -----
IMPs were originally designed for team
competition. IMP PAIRS is simply an averaging of
your opponents' results before such a comparison
takes place; you are pitted against the "average
opponent" when playing IMP Pairs.
Playing IMPs, if you make 430 while others make
420, you have a raw score difference of a measly 10.
This is worth ZERO IMPs. Were you playing MatchPoints,
though, 430 would beat ALL the other pairs with their
420 scores; you would receive ALL the MatchPoints on
such a board. (This, by the way, explains the popularity
of No Trump contracts among MatchPoint players.)
Similarly, if EVERYONE ELSE scores +100 on a
hand, you will get all the MatchPoints with any score
above +100: +110 would get you the same fine result as
+1100 would!
At MatchPoints, then, you only need to beat the
score achieved by others who play the same hand. It
does not matter BY HOW MUCH you beat them.
At IMPs, though, it is not enough to beat the
others who hold the same hand as you. In order to
make headway, you must beat them by as much as
possible! If you score +110 as opposed to +100 you
will score a lot of MatchPoints, but a net difference
of (110 - 100 = ) 10 would net you ZERO IMPs. +1100
versus everyone else's +100, on the other hand, is
worth (1100 - 100 = ) 1000 net points, or a whopping
+14 IMPs.
----- The Effect on Strategy -----
How does this difference in scoring methods
affect your decisions at the table? Plenty!
At MatchPoints, making an overtrick in an
undoubled, non-vulnerable 4H while others make only
ten tricks means a "top" board (i.e. all the
MatchPoints available). But at IMPs, it means only
(450 - 420 = ) 30 points, or 1 measly IMP! With so
few IMPs at stake, this would be considered a "flat"
or "near-flat" board at IMPs. Many such hands which
are so exciting at MatchPoints ("Can you make that
critical extra trick?") are a total yawn at IMPs!
On the flip side, going down in 4H while
all others make 10 tricks is a "bottom" board, or
ZERO MatchPoints. At IMPs, though, you have just
lost (420 + 50 = ) 470 points in total, which
converts to a disastrous -10 IMPs.
From this we discern that, at IMPs, you
would almost NEVER risk the contract for an overtrick.
The risk (-10 IMPs here) far outweighs the gain
(1 IMP). At MATCHPOINTS, however, that overtrick
may mean the difference between a top and an so-so
result, so you MIGHT, if you see the chances as
better than 50%, put your contract at risk to
try for an overtrick (especially if you think
everyone will be in the same contract as you).
Similarly, on defence, you would always cash
the setting trick at IMPs to ensure defeating
the contract. But, at MatchPoints, an extra
undertrick might be worth the risk of NOT
cashing the setting trick in the hopes of
setting the contract TWO tricks!
"So," you might ask, "if going down in
a game which everyone else makes is a disaster at
both forms of the game, what's the difference?
Isn't it just one bad board?"
The difference is that at MatchPoints you
can recover by making an overtrick in 3D on the
very next board while everyone else makes only nine
tricks. At IMPs, this would only recover ONE of
the ten IMPs you lost going down in 4H earlier!
Because you need hands where big numbers are at
stake, it is much harder to recover from disasters
at IMPs BECAUSE THERE ARE FAR MORE "FLAT" OR
"NEAR-FLAT" BOARDS AT IMPs!
----- Bidding Versus Play -----
In MatchPoints, "the play is the thing". An
overtrick or an extra undertrick means EVERYTHING
if it distinguishes your score from everyone else's.
There are few "flat" boards at MatchPoints. In a
typical 24-board session at MatchPoints, you may
have 2 or 3 "flat" boards. In a typical 24-board
match at IMPs, you may have 12-18 such "flat" or
"push" boards. :(
At IMPs, bidding is paramount. Miss a slam
or a makeable game and you're in trouble. Squeezing
out an extra overtrick or extra undoubled undertrick
via careful play on the next hand will NOT recover
your loss.
The above distinction explains the expression:
"IMPs is for BIDDERS; MPs is for CARD-PLAYERS!"
It also explains why MatchPoints is a much more
intense game where EVERY board has equal importance.
A delicately bid and played 7NT contract will not
gain you any more or any fewer MatchPoints than the
lucky overtrick you made in 1C the hand earlier.
At IMPs, however, you can safely fall asleep during
the 1C hand--as long as you wake up for the 7NT one!
In this regard, by the way, IMPs is closer to Rubber
bridge than MatchPoints is.
Bottom line: At IMPs, the big "swing" hands
with a lot of points at stake (e.g. difficult games,
slams and doubled contracts) matter most. At
MatchPoints, all boards are equally important.
----- Competing for the Part Score -----
The area where the two games diverge most is
in competitive part score bidding. Consider this
situation: You have bid 3D, rather confident of
making. The vulnerable opponents compete to 3S.
You can't be 100% certain, but your instincts tell
you that 3S will likely go down one. Should you
double?
At IMPs, the difference between 3S down
one doubled versus undoubled is (200 - 100 = )
100, or THREE IMPs. If they make, though, the
difference is (730 - 140 = ) 590, or ELEVEN IMPs.
Hence, you'd better be VERY confident of 3S going
down before doubling it at IMPs! Otherwise, you
would do better to pass 3S. If it does go down
one, the board will be flat, since (110 - 100 = )
10 points means ZERO IMPs.
At MatchPoints, however, you were slated
for +110 in 3D, so +100 in 3S will NOT compensate
you. You may get a bottom board if everyone else
is allowed to collect +110 in 3D. Hence, to
"protect" your +110, you might double 3S and hope
to nip it one for +200 and a GREAT score at MPs.
Bottom line: save those close doubles for
MatchPoints, not IMPs!
At MatchPoints, you will often strain to
balance the enemy into an unmakeable contract.
Nothing does your game better than pushing the
opponents to 3H and collecting +50 while
everyone else is -110 against 2H. If balancing
against their 2H risks the odd -800 because of
a trump stack against you, so be it. As long
as you collect more +50s than -800s you'll do
fine in the long run at MatchPoints.
At IMPs, though, those -800s had better
be FAR fewer. Getting +50 versus -110 is worth
(50 + 110 = 160) FOUR IMPs. -800 versus
-110 loses (800 - 110 = 690) TWELVE IMPs,
and such disasters are harder to recover from,
with fewer decisive boards at IMPs than at
MatchPoints. :(
Bottom line: save your balancing heroics
and aggressive part score competing for when
you're playing MatchPoints, not IMPs!
----- Sacrificing -----
Let's take another scenario. They have
bid 4H, vulnerable. You figure that they have
a better-than-even chance of making it. Your
side, on the other hand, can bid 4S, get
doubled, and go down -500, 120 points better
than you will spit up for 4H if it makes.
Should you sacrifice in 4S, then?
At MatchPoints, the answer is YES.
If they do make 4H you are have improved
your score from -620 to -500. Yes, if 4H
goes down, your -500 will not look good
opposite everyone else's +100. But as
long as 4H has a better than 50% chance
of making, you will gain more often than
you will lose IN THE LONG RUN.
At IMPs, the answer not so clear.
4S will only improve your score by
(620 - 500 = 120) THREE IMPs. If, on
the other hand, 4H goes down one, you
will have foregone the +100 for -500,
a 600 point difference for MINUS TWELVE
IMPs. Since your sacrifice has to be
"correct" (i.e. 4H has to make) 4 times
to 1 for those 3 IMPs to equal the 12 IMPs
you might be missing, 4H should have an 80%
or better chance of making before you should
sacrifice against it! At MatchPoints, your
sacrifice only had to be right more than 50%
of the time to pay off in the long run!
Bottom Line: At MatchPoints, sacrifice against
anything the opponents bid confidently. At IMPs,
sacrifice only against those contracts which are
underwritten by Lloyds of London! :)
----- When To Play SAFE at MatchPoints -----
After an auction such as 1NT:3NT, it is
reasonable to assume that virtually EVERYONE will
be in the same contract. This being the case, at
Matchpoints we MUST take as many tricks as we can.
If this runs a slight risk or going down, so be it.
But what if we are in a contract that many in
the field might NOT find, we should play safely to
make--just as we would at IMPs. But how can we
know where OTHER pairs will be in a given hand?
If, during the auction, either you or your
partner faced a "crossroads" where either of two
actions looked attractive it is fairly safe to
assume that approximately half of the people took
the OTHER fork in the road. If YOUR decision
turns out to be a makeable contract while others
will be less profitable, MAKE YOUR CONTRACT. In
essence, then, we say to ourselves: "Hmm, we seem
to have stumbled into a good contract here. Better
make it!"
If it appears that the others might be in
a more profitable contract, we may need to stretch
for overtricks. The typical case is one where we
are in 3NT while others may be in 4H or 4S. If we
calculate that those in the other contract will be
slated to make 420, we need to try for an overtrick
to make 430 in 3NT. Here we are saying to ourselves:
"Gotta find some way to keep up with the Joneses!"
At Matchpoints especially, we need to develop
an additional routine to our normal "count our
tricks" work habit. We need to ask ourselves:
"What is everyone ELSE likely to be in here? And
how many tricks are THEY likely to take?" Then,
we need to find a way to BEAT that alternate score.
Practice doing this on EVERY hand.
----- Questions -----
1. You are in 4S doubled and vulnerable at IMPs.
You COULD make an overtrick by playing a Club,
but a 5-0 Club break (a 3.94% chance) will
produce a ruff for down one. Should you risk
your contract at IMPs here?
2. You are in 4S doubled and vulnerable at MPs,
a contract that few others will find. You
COULD make an overtrick by playing a Club,
but a 5-0 Club break (a 3.94% chance) will
produce a ruff for down one. Should you risk
your contract here at MatchPoints here?
----- Rubber and Board-A-Match -----
In Rubber bridge, the pair with the better
cards will almost invariably win. Even a few
620's and 1430's will more than compensate the
-50's and -100's that the other side will score
for defeating contracts. At Rubber bridge, then,
"cardracking" (i.e. the ability to hold good
cards) is of paramount importance. A good rubber
bridge player will never risk hir contract for an
overtrick. In this regard, then, Rubber is exactly
like IMPs.
But because Rubber is played by pairs, not
teams, one would more accurately state that Rubber
is like IMP PAIRS. Aside from the conversion from
raw scores to IMPs, though, what is the difference
between the two? This contrast can be expressed in
one word: equity. At IMP Pairs, all the pairs
sitting in our direction will be holding the same
cards. Our task at IMP Pairs, as in life, will be
to do the very best that we can with the cards that
we are dealt.
In a sense, then, Rubber could be considered
"IMP Pairs without a field" of players with whom we
would compare our results. This explains its
decline in popularity relative to IMPs.
In every Fall ACBL National event there is an
Board-a-Match event called the "Reisinger".
Board-a-Match is a TEAM event where whichever team
does better than the other wins the board and gets
one point. Ties or "pushes" don't count (i.e. each
team gets a half a point). So if one team makes 4S
for 420 at one table while their counterparts on the
other squad at the other table make 430 via an
overtrick in 3NT, the second team wins one point.
In this way, while Rubber may be considered "IMPs
without a field", Board-a-Match could be viewed as
"Matchpoints without a field". As such,
notwithstanding the unquestioned prestige of the
Reisinger, Board-a-Match is the least common form
of the game.
----- The Effect on Systems and Conventions -----
An effective pair may prepare differently for an
important event, depending upon the form of the game.
Before a Matchpoint event we might wish to brush up on
our playing skills by leafing through Louis Watson's
classic tome, "Play of the Hand" and on defence. We
may review such works as Hugh Kelsey's "Killing Defence"
or Rainbow Lessons #10 ("Defensive Signalling") and #11
("Defence"). We would also want to concentrate on our
competitive bidding. We might look at references on the
Law Of Total Tricks (e.g. "Following the Law", "Points
Schmoints" and "To Bid or Not to Bid"), overcalling
(as with Mike Lawrence's "The Overcall") and on doubles
(e.g. Rainbow Lesson #8: "Competing with Doubles" and,
perhaps, KaleidoScope Lesson #3: "Defensive Doubles").
In preparing for an important IMPs contest, we
would tend to concentrate on our slam bidding. Some
pairs will play 2/1-GF or Forcing Club system at IMPs,
SAYC at Pairs. At IMPs, some pairs will even play 2/1-GF
in first and second seat (when slams are more likely) and
SAYC in 3rd and 4th seat (when Partner's pass dims our
slam hopes). Some 2/1-GF pairs will play a forcing
1NT response to 1H or 1S at IMPs, but prefer to retain
a non-forcing 1NT response at Matchpoints. This will
require that they use a gadget such as a non-forcing
2NT reply (10-12, doubleton in Opener's major) or
the Toddler 2D response (which can be investigated at:
http://www.escape.ca/~cpw/toddler.htm) while playing
Matchpoints. Others may prefer a weak 1NT opening at
Matchpoints, strong 1NT's at IMPs.
Many expert pairs play DONT at IMPs, CAPP at
MatchPoints. To understand this, we need to review
these two conventions:
DONT: Over their 1NT opening bid:
Double = 1-suited takeout. Advancer asks via 2C.
2C, 2D or 2H = 2-suited with the bid suit and
any higher ranked suit.
CAPP: Over their 1NT opening bid:
Double = Penalty
2C = Any 1-suiter. Advancer bids 2D to ask.
2D = Both majors.
2H = Hearts and an unspecified minor.
2S = Spades and an unspecified minor.
Why play DONT at IMPs but NOT at Matchpoints?
Consider the 2D overcall from this Advancer's point
of view:
S- Q10xx H- xx D- Qxx C- Jxxx
Removing the 2D overcall to a major will work
out well IF that major happens to be Spades. It may
be disastrous if Overcaller's major is Hearts, though.
Hence, most players will PASS here. If Overcaller's
major turns out to be Spades, this will not be a
disaster at IMPs: +90 versus +110 if both contracts
make 8 tricks. At Matchpoints, however, we MUST be
in the right strain.
Playing CAPP, Overcaller would bid hir major
directly (e.g. 1NT-2H or 1NT-2S). If Hearts, the
above Advancer will remove to the minor via 2NT. If
Spades, the pair will have found its major suit fit.
DONT, then, is SAFER--a critical consideration at
IMPs. CAPP will find any major suit IF THERE
IS ONE, but will risk going to the 3-level if the
pair's fit is in a MINOR.
All of these adjustments address the basic
needs of the partnership. At IMPs, we need to
avoid losing BIG amounts, while generating any
that are available to us. We don't "sweat the
small stuff" at IMPs. Only at MPs do we need to
fine tune our bidding to get the very best score.
----- In Conclusion -----
Matchpoints, then, is a simple matter of edging
our the opposition. It is an "either/or" proposition.
You either beat their score or you don't. The effect
is that games, doubles and sacrifices need only a
50% chance of success.
IMPs is a game of AMOUNTS where the risk-reward
ratio is usually more complex than a straight 50-50.
Rather, it is a game of percentages. For example,
a vulnerable game is worth bidding at IMPs if it
succeeds 38.71% of the time. A non-vulnerable game
contract requires only a 45.24% chance of success.
This is because the cost of going down one in, say,
4H is the loss of the 140 for 3H, plus the 50 point
penalty. Compare this 190 we "lose" to the +420 we
would make if the game WERE to make and we come to
45.24%. These more complex percentages, in contrast
to the 50-50 world of Matchpoints, gives rise to
the expression:
"Matchpoints is a coin toss; IMPs is a crap shoot!"
And that, in a nutshell, is the difference between
IMPs and MatchPoints. :)
---------- Final Quiz -------------
1a. After 1NT:3NT, Partner leads the H-9 and we hold:
S- Kxx H- AQ432 D- Q9xx C- x. Dummy has:
S- xxx H- KJ5 D- J10xx C- AKxx. What do you
play at IMPs when Declarer plays the H-5 from Dummy?
1b. After 1NT:3NT, Partner leads the H-9 and we hold:
S- Kxx H- AQ432 D- Q9xx C- x. Dummy has:
S- xxx H- KJ5 D- J10xx C- AKxx. What do you
play at MPs when Declarer plays the H-5 from Dummy?
2a. S-KQxx H-xx D-Qxx C-xxxx None vul, IMPs. The auction
proceeds: 1S-2H-2S-3H-P-P back to you as Responder. What
should we do here at IMPs?
2b. S-KQxx H-xx D-Qxx C-xxxx None vul, IMPs. The auction
proceeds: 1S-2H-2S-3H-P-P back to you as Responder. What
should we do here at MatchPoints?
2c. S-KQxx H-xx D-Qxx C-xxxx None vul, IMPs. The auction
proceeds: 1S-2D-2S-3D-P-P back to you as Responder. With
the opponents bidding DIAMONDS this time, what should we
do here at IMPs?
3. Which of the following are more common at MatchPoints than
at IMPs?
a) Competitive Doubles
b) Help Suit Game Tries
c) Balancing Doubles on marginal values
d) Safety Plays
4a. We have bid 3C, confident of +110 there. The opponents,
who are not vulnerable, compete to 3H. We calculate that 3H
will go down one slightly more often than 3H will make. Down
two is very unlikely. Should we double?
4b. We have bid 3C, confident of +110 there. The opponents,
who ARE vulnerable, compete to 3H. We calculate that 3H will
go down one slightly more often than 3H will make. Should we
double?
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The KaleidoScope Series, at 8:00 A.M. and either 3:00 P.M. (Monday and Wednesday) or 7:00 P.M. (Tuesday and Thursday) PST from Monday to Thursday, is a lecture program on a variety of subjects: Bidding Light, Maximum Flexibility, Defensive Doubles, LOTT versus "Got More, Bid More" and Squeezes. Unlike the FireSide and 5th Chair sessions mentioned above, the Kaleidoscope Series is a semi-private lesson program for our students. Nevertheless, you are invited to stop by and participate. The KaleidoScope Series, directed more at that intermediate player than the Rainbow and Spectrum, has quickly become one of our most popular. For $60 for five invaluable lessons ($100 for two series, $150 for all three series) this may be the best bridge instruction available anywhere!  CLICK HERE to email your registration. In the meantime, why not click on the lessons below and start learning now ? |
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