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Louis Stumpers
L Stumpers 
Number of games in database: 55
Years covered: 1932 to 1969
Overall record: +13 -32 =10 (32.7%)*
   * Overall winning percentage = (wins+draws/2) / total games.

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Most played openings
D94 Grunfeld (3 games)
B59 Sicilian, Boleslavsky Variation, 7.Nb3 (2 games)
C65 Ruy Lopez, Berlin Defense (2 games)
D45 Queen's Gambit Declined Semi-Slav (2 games)
E60 King's Indian Defense (2 games)

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(born Aug-30-1911, died Sep-27-2003, 92 years old) Netherlands

[what is this?]

Frans Louis Henri Marie Stumpers was born in Eindhoven, Netherlands, on 30 August 1911. (1) He was champion of the Eindhoven Chess Club in 1938, 1939, 1946, 1947, 1948, 1949, 1951, 1952, 1953, 1955, 1957, 1958, 1961 and 1963, (2) and champion of the North Brabant Chess Federation (Noord Brabantse Schaak Bond, NBSB) in 1934, 1935, 1936, 1937, 1938, 1939, 1940, 1941, 1942, 1943, 1944, 1946, 1948, 1949, 1950, 1951, 1952, 1953, 1954, 1955, 1959, 1961, 1962, 1963, 1964, 1965, 1966 and 1967. (3) He participated in five Dutch Chess Championships, with a 4th place in 1948, (4) and represented his country at the 1st European Team Championship, in Vienna in 1957 (two games, vs Josef Platt and Max Dorn). (5) From 1945 and until about 1956, he was first Secretary and then Chairman of the NBSB. (3)

Stumpers was a physicist, and worked for the Philips company as an assistant from 1928. During 1934-1937, he studied at the University of Utrecht, where he took the master's degree. (6) In 1938 he was again employed at Philips, (6) and at a tournament in 1942, he supplied the hungry chess players with food from his employer. (3) After the war, he made a career in physics, with patents and awards on information ('radio') technology. He received degrees from several universities and colleges, including in Poland and Japan. (1, 3, 6) He retired from Philips in 1972, but continued teaching, (6) partly as professor at the University of Utrecht (1977-1981). (7) He was also Vice President (1975-1981) and Honorary President (1990-2003) of URSI, the International Union of Radio Science. (8)

Louis Stumpers married Mieke Driessen in 1954. They had five children, three girls and two boys. (6)

1) Online Familieberichten 1.0 (2016), Digitaal Tijdschrift, 5 (255),
2) Eindhovense Schaakvereniging (2016), http://www.eindhovenseschaakverenig....
3) Noord Brabantse Schaak Bond (2016), Their main page:
4) (2016),
5) Olimpbase,
6) K. Teer, Levensbericht F. L. H. M. Stumpers, in: Levensberichten en herdenkingen, 2004, Amsterdam, pp. 90-97, Also available at
7) Catalogus Professorum Academiĉ Rheno-Traiectinĉ,
8) URSI websites (2016), and

Suggested reading: Eindhovense Schaakvereniging 100 jaar 1915-2015, by Jules Welling. Stumpers' doctoral thesis Eenige onderzoekingen over trillingen met frequentiemodulatie (Studies on Vibration with Frequency Modulation) is found at

Last updated: 2017-06-26 02:43:54

 page 1 of 3; games 1-25 of 55  PGN Download
Game  ResultMoves YearEvent/LocaleOpening
1. L Stumpers vs J Lehr  1-0191932EindhovenD18 Queen's Gambit Declined Slav, Dutch
2. Prins vs L Stumpers  1-0391936NED-ch prelimB20 Sicilian
3. L Stumpers vs E Spanjaard  1-0551938Dutch Ch prelimE02 Catalan, Open, 5.Qa4
4. E Sapira vs L Stumpers 0-1251938NBSB - FlandersD94 Grunfeld
5. A J Wijnans vs L Stumpers  1-0361939NED-chB05 Alekhine's Defense, Modern
6. J van den Bosch vs L Stumpers  ½-½581939NED-ch11A48 King's Indian
7. L Stumpers vs S Landau 0-1411939NED-ch11D33 Queen's Gambit Declined, Tarrasch
8. H van Steenis vs L Stumpers  1-0251939NED-chB02 Alekhine's Defense
9. L Stumpers vs H Kramer  0-1361940HilversumE25 Nimzo-Indian, Samisch
10. A J van den Hoek vs L Stumpers  1-0271941BondswedstrijdenB10 Caro-Kann
11. T van Scheltinga vs L Stumpers 1-0351942NED-ch12D94 Grunfeld
12. W Wolthuis vs L Stumpers  ½-½521946NED-ch prelim IC58 Two Knights
13. L Stumpers vs J H Marwitz  1-0401946NED-ch prelim ID31 Queen's Gambit Declined
14. G Fontein vs L Stumpers  ½-½261946NED-ch prelim ID94 Grunfeld
15. L Stumpers vs H van Steenis 0-1241946NED-ch prelim ID28 Queen's Gambit Accepted, Classical
16. C B van den Berg vs L Stumpers  1-0581946NED-ch prelim ID19 Queen's Gambit Declined Slav, Dutch
17. L Stumpers vs Euwe 0-1301946NED-ch prelim IE60 King's Indian Defense
18. L Stumpers vs Cortlever  ½-½501946NED-ch prelim IE60 King's Indian Defense
19. L Stumpers vs Grob 1-0601947Int BA55 Old Indian, Main line
20. L Stumpers vs H van Steenis  0-1331947Int BD23 Queen's Gambit Accepted
21. Tartakower vs L Stumpers 1-0241947Int BD74 Neo-Grunfeld, Nxd5, 7.O-O
22. V Soultanbeieff vs L Stumpers  ½-½461947Int BD96 Grunfeld, Russian Variation
23. L Stumpers vs F Henneberke 1-0431948NED-ch14C92 Ruy Lopez, Closed
24. J T Barendregt vs L Stumpers  0-1261948NED-ch14C86 Ruy Lopez, Worrall Attack
25. L Stumpers vs C Vlagsma  0-1451948NED-ch14C65 Ruy Lopez, Berlin Defense
 page 1 of 3; games 1-25 of 55  PGN Download
  REFINE SEARCH:   White wins (1-0) | Black wins (0-1) | Draws (1/2-1/2) | Stumpers wins | Stumpers loses  

Kibitzer's Corner
< Earlier Kibitzing  · PAGE 293 OF 293 ·  Later Kibitzing>
Premium Chessgames Member
  The Wanderer: What if there were three kinds of candles: green, vanilla, and turquoise. The green candles take five seconds to light and three of them to light another candle. The vanilla candles are wet and need sixteen seconds to light. And the turquoise candles are trick candles that take five seconds to light, but once lit there's only a 1/3 chance they'll remain lit long enough to light another candle.

If one vanilla candle is lit in the center of a large crowd of people who haven't seen how the various candles work yet, what will happen?

Premium Chessgames Member
  al wazir: <If one vanilla candle is lit in the center of a large crowd of people who haven't seen how the various candles work yet, what will happen?> I never use vanilla candles. Make it chocolate instead.
Premium Chessgames Member
  Sneaky: Sneaky: <The speed of light can neither be calculated nor measured. Its value is a *defined* quantity> Pi and the golden ratio are defined quantities--the speed of light is and has always been measured empirically. All you've done is pointed out that the meter is (currently) defined using the speed of light. (If I recall, at first it was defined in relation to the earth's circumference.) Anyhow, c certainly can be measured; famously measured first in the 19th century, by studying the motions of the moons of Jupiter with telescopes and stopwatches.

So you're not wrong saying it's exactly 299,792,458 m/s -- but you're forced then to confess you don't know the exact length of a meter!

Premium Chessgames Member
  zanzibar: Glad to see the correction about the speed of light being measurable.

All you have to do is count to one:

c = ħ = 1.

(Now, if only we could just set π = 1, we could cut down mistakes by at least ½, if not 1)

Premium Chessgames Member
  al wazir: <Sneaky: So you're not wrong saying it's exactly 299,792,458 m/s -- but you're forced then to confess you don't know the exact length of a meter!> Oh, but I do: <1/299,792,458 of the distance light travels in a vacuum in one second.>
Premium Chessgames Member
  john barleycorn: yes, and 1 second is

299,792,458 m divided by 299,792,458 m/s

Premium Chessgames Member
  beatgiant: <Sneaky>
<Pi and the golden ratio are defined quantities> Most <units of measurement> are arbitrarily defined, but the quantities associated with Pi and the golden ratio are not. They represent universal mathematical relationships that can be estimated or represented exactly by infinite series or continued fractions etc., and would be the same for intelligent beings on Proxima Centauri b, if they exist and care about math.
Premium Chessgames Member
  john barleycorn: Pi and the golden ratio are real numbers not per se units of measurement. they act for example as multipliers or divisors in measurements. like 299,792,458.
Premium Chessgames Member
  beatgiant: I understand the state of Indiana actually did almost pass a law redefining pi as 3.2. If they were really able to do that, it would make life a lot easier for schoolchildren all over the galaxy...
Premium Chessgames Member
  john barleycorn: <beatgiant> guess why pi is called an irrational number. Kudos to the pragmatic approach of the state of Indiana. I think I read it in one of Martin Gardner's books but with 4 (instead of 3.2).
Premium Chessgames Member
  beatgiant: <john barleycorn> You can't make this stuff up

Say, I wonder if <Sneaky> is from Indiana. The ability to square the circle would explain why he's doing better than both of us in the ChessBookie game.

Premium Chessgames Member
  john barleycorn: <beatgiant: <john barleycorn> You can't make this stuff up ...>

only in the US of A :-)

Premium Chessgames Member
  Sneaky: <beatgiant>

<Most <units of measurement> are arbitrarily defined>

Like the inch, the ounce, the hour? Of course. And that's why they aren't perfectly defined. If I told you that a "Sneaky foot" was the length of my right foot, you'd never be able to know its length in centimeters until you meet me and do the measurement, and even then, it's going to have an error margin.

<but the quantities associated with Pi and the golden ratio are not.>

Of course—you can't compare an exact value like pi to the "Sneaky foot", they are cut from a different cloth.

I fully agree they are not *arbitrarily* defined, but they are most certainly *defined* and that's all my small point was that I directed to <al wazir>.

Pi can be defined in at least three ways that I know of: you can define it conceptually, such as "the ratio of a circle's circumference to its diameter" (and even though that's the one we learn in school you could define it in terms of things that seemingly have nothing to do with circles!)

Or you can define it as an infinite series and Euler, Ramanujan, and countless others did.

Or you can define it as a recursive fraction like this graphic shows on Wikipedia:

There probably are dozens of other ways to define it using geometry, probability, topology, and branches of math far over my head.

On a quasi-philosophical note, I don't believe any of these definitions are more "primal" than the others. We've all been taught to think of it as the circumference/diameter but if you want to think of pi as (4/1)*(4/3)*(8/3)*(8/5)*(12/5)*(12/7)*(16/7)*(16/- 9)*... that's equally as valid, IMO. It's not fair to say that one is a consequence of the other, and not vice versa. In our minds it may work that way, but math itself is disinterested in our emotions. Perhaps on Proxima Centauri b the Ramanujan series is their initial introduction to the topic and only later do they learn that it also happens to be the ratio of circumferences to diameters.

Premium Chessgames Member
  john barleycorn: <Sneaky: <beatgiant>

<Most <units of measurement> are arbitrarily defined>

Like the inch, the ounce, the hour? ...>

I hink <beatgiant> has inch vs. centimeter etc. in mind. The units are indeed arbitrary. what is important that they can be converted from one measurement system to the other.

Premium Chessgames Member
  beatgiant: <Sneaky>
Well, that's a bit like arguing that the square root of two could be defined as an infinite series or continued fraction first, and only then derive the fact that it happens to yield two when multiplied by itself.

Suffice it to say, if you have defined things like circles, gaussian probability distributions etc., pi will come out of those without further invention. But I don't want to go on and on about this and take the forum off topic.

Premium Chessgames Member
  john barleycorn: <<sneaky> On a quasi-philosophical note, I don't believe any of these definitions are more "primal" than the others.>

Being more "primal" is not a criterion for a definition. In fact, the "primal" ones may be clumsy and being replaced but it is a matter of taste where you put the difficulties. In the definition or in the theorems.

Premium Chessgames Member
  beatgiant: <where you put the difficulties. In the definition or in the theorems.>

Or both. If, as <Sneaky> suggests, we define a circle as a figure whose distance around is a certain Ramanujan sum times its distance across, and then prove a theorem that the points on a circle are equidistant from a center, I would have difficulty with both the definition and the theorem.

Aug-15-17  ughaibu: The probability of two randomly selected non-zero natural numbers being co-prime, is six divided by pi squared.

So, the number of ways to define pi is, presumably, infinite and the ways to define it, arbitrary.

Premium Chessgames Member
  beatgiant: <ughaibu>
The original controversy was <pi is a defined quantity> versus <pi represents universal relationships>. Showing that there are lots of things that are related by pi tends more toward the latter.
Aug-15-17  ughaibu: Is there really a dilemma?
Premium Chessgames Member
  beatgiant: <ughaibu>
The original contrast was speed of light (measured) versus pi and the golden ratio (defined). But it all depends what <Sneaky> means by those terms.
Aug-15-17  ughaibu: Okay, I guess I should read through the earlier posts.
Premium Chessgames Member
  al wazir: <ughaibu: The probability of two randomly selected non-zero natural numbers being co-prime, is six divided by pi squared.>

Prime numbers become increasing sparse with increasing size (the number of primes .lt. n scales asymptotically as n/ln n as n → ∞). Accordingly, composite numbers become increasingly dense as n → ∞. But as n → ∞ the number of primes that *might* divide n grows without bound, so it is not intuitively obvious that the probability that two randomly chosen natural numbers are coprime is nonzero.

I looked up the proof of this remarkable theorem ( There are two elementary demonstrations there. Both have statements like "the probability that k divides a is 1/k." But one thing troubles me. If k > a, the probability that k | a is *zero*.

The simpler of the two proofs goes on to say

<Now, k was just one possibility for the greatest common divisor of two random numbers. Any number could be the gcd(a,b). Furthermore, since the events gcd(a,b) are mutually exclusive (the gcd of two numbers is unique) and the total probability of having a gcd at all is 1 leads to>

1 = ∑q/k^2,

where the summation runs from 1 to ∞.

But it seems to be that for any *particular* pair (a, b) the sum should be truncated at min(a,b).

What am I missing?

Premium Chessgames Member
  beatgiant: <al wazir>
I don't think you are missing anything. To get the result over all numbers, one takes a limit as min(a,b) goes to infinity.
Aug-17-17  ughaibu: Here's some fun in the phi, pi and (almost) squaring the circle story:
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