Tag: odds

Bayesian Recognition

We don’t meet often, but every time we talk, she reminds me that I had failed to recognize her the first time we had met after graduating together from school. Yes, I could claim in my defence that I was seeing her for the first time in over six years. While that might be a valid excuse for most people, it doesn’t apply to me, since I normally claim to have superior long-term memory. If I’ve seen you somewhere before, I ought to recognize you. The only times I don’t I’m pretending, since I don’t want to embarrass you (and myself) by recognizing you while you don’t recognize me (see this incident for an example of this).

The reason for my failure that cold Bangalore evening in December 2006 was that my Bayesian system had failed me. Let me explain, in the process giving you an insight into my Bayesian system which I use to recognize you when I meet you.

About a month or two back, I was at a friend’s wedding, which is where I hit upon this term “Bayesian recognition” to explain this phenomenon  (which I’ve been practicing for ages). Now, this friend whose wedding I was attending was one year my junior at two different schools. As you might expect at an event where you and the host share more than one social network, there were a lot of familiar faces. Some people I knew fairly well, and could easily recognize. But the others had to go through a “Bayesian search”.

So when I saw someone who was one of three people I know – let’s say X, Y and Z. In order to determine which of these this person is, I would ask myself two questions – firstly, what were the prior odds that the person I saw could be each of X, Y or Z. Secondly, what were the odds of each of X, Y and Z being there at that event. Note that the latter is important. For example, if someone at the event looks like you and I know (for example) that you are currently in another country, despite the strong resemblance I can discount the possibility that that person is you, and go ahead with my search.

Note that this differs from “frequentist recognition”, where I only look at the person’s face and try and understand who he/she most resembles, without any thought to the odds that that person is there. Frequentist recognition can lead to a large number of false positives, and after a few rounds of embarrassment, you start giving up on recognizing, and many a possible reunion thus gets missed. Bayesian recognition, on the other hand, restricts your field of search (to the people who you give good odds of being there), prevents you from being distracted and increases your chances of making a good recognition.

So why did Bayesian recognition fail me when I met this former classmate back in 2006? The problem was her company. She had come for this Deep Purple concert with another friend of mine, who was my classmate in another school (and who I had been in touch with, and so easily recognized). I had no clue that these two were friends (it turned out they didn’t know each other that well – they had come there with a common friend). So when this girl (the one I didn’t recognize) popped up with “Hey SK! Do you remember me?” I assumed that she was someone I knew from the same school as the other girl I was meeting, and that wrongly restricted my search space. And so my mind was trying to map her to my friends from school 1, while she happened to be a friend from school 2. And my search returned a blank, and my legendary long-term memory skills were embarrassed.

I must mention here, though, that this is possibly the only time that my Bayesian recognition model has acted up, and refused to recognize someone I know. There have been 2-3 false positives, but this has been the only negative. And when you consider the sample size to be all the people I have recognized in different places, this is small indeed.

Oh, and after failing to recognize her then, I’ve kept in touch with this friend.

Whether to surprise or not

Today, my wife turns twenty five. It hasn’t been a good birthday so far, for she feels depressed that she’s growing old. It doesn’t help matters that I’ve failed to surprise her, while on my birthday six months back she had put together a series of fantastic surprises. In my defence, I treated her to an afternoon of unlimited shopping a couple of days back,which I had assumed was her”birthday gift”.

Anyway, the point is that it had been brought to my notice before I went out somewhere this evening that I’d failed to materialize with a “birthday gift” and I was wondering if I should get something on my way back. It is not like I didn’t have ideas. I had several. But as I went through them one by one I realized that for each of them, there was a credible rebuttal she could come out with for each of them that would make it seem like there was no “thought” behind that gift and the only reason I had brought it was that she was unhappy.

I reasoned that irrespective of what had happened in the intervening couple of hours when I was out, she would still be upset with me at the end of it. Given that she would be upset with me, the odds that the gift I would bring would completely melt her and she would be satisfied would be miniscule. Instead, I would only have to endure more sulking, with the added charge of my trying to bribe her out of her anger.

I guess the big problem with me that I’m too cold and rational most of the time (the few occasions when I get emotional, I go crazy and cry loud enough to bring my whole apartment complex down). So the rationalist in me decided to make the rational decision that the chances of winning over my wife with a superb gift was so low that it would not justify the effort involved in bringing that surprise. So I came home empty handed.

My wife is inside the bedroom now, pretending to read a book that isn’t particularly interesting, while I blog this sitting in the hall, having taken control of the TV and watching the French Open final. I guess I was guilty of not giving myself that chance to turn her over today. But then, I didn’t spend all that mind space in trying to find that superb gift. I told you right, that I’m too cold and rational most of the time. And I write about too many things on this blog.

What the hell was Vettori thinking?

I’m writing this post in anger. In disgust. At the sheer lack of strategic vision shown by Royal Challengers Bangalore captain Daniel Vettori. What the hell was he thinking when he threw the ball to Virat Kohli for the 19th over, with 43 required off two overs? Yes, there had been a miscalculation earlier which meant that one of the last five overs had to be bowled either by part-timer Kohli, or by Raju Bhatkal who had been torn apart in his earlier two overs. While it is hard to pardon miscalculation in a twenty over game, it is nothing compared to the strategic error of the 19th over.

When overs sixteen to eighteen were bowled by Zaheer, Vinay and Zaheer respectively, I thought it was a tactical masterstroke by Vettori to keep the one extra over to the end. Given the skyrocketing required run rate, I thought it was a great idea that he was trying to put the match beyond Chennai Super Kings by the 19th over itself. And it worked well. From 75 needed off 5 overs, the equation was brought down to 43 off the last two overs (now, it is reasonable to expect Zaheer and Vinay to go at around 10 an over in the slog overs). And then what happened?

You have two overs left, 43 runs to win. You have a reasonably experienced medium pacer who is generally good at bowling at death, but is also prone to buckling under pressure. And you know you can’t trust whoever the other bowler is going to be. What you want is to have your good bowler bowl without any pressure on him. Without any pressure, you can expect him to go for about 10-15 in the 19th, leaving the batsmen to score nearly 30 off the last over – which would tilt the odds significantly in favour of the part timer who would bowl that over, since the pressure would be on the batsmen.

Instead, what do you do? Give the part timer the 19th over. He has no answers for Morkel’s slogging and edging, and goes for 28, leaving Vinay to defend 15. Now, it is Vinay (who is vulnerable under pressure) who has to bowl under pressure, and the batsmen know that. It is a miracle that the match went down to the last ball.

Of course you might say that I wouldn’t have reacted so angrily had either RCB won or Kohli had gone for less in his over. That’s not true. The match was in RCB’s pocket, to be won. The probability of victory reduced significantly the moment the ball was thrown to Kohli (for the 19th over). The ultimate result doesn’t matter. I would have blasted Vettori even if we had won.

Now, there is another uncharitable explanation that comes to mind, and I’m not very proud that this comes to mind. Was it mere incompetence or some sense of malice on the part of Vettori to give the 19th over to Kohli? I’m not talking about bookmakers here, I respect him too much for that. But think about it. Just yesterday, both Mint and Cricinfo ran articles talking about IPL 5’s poor TV ratings so far. The BCCI Chairman N Srinivasan (who not so coincidentally owns CSK) said that the answer to increasing TRPs was to play on batting-friendly high-scoring pitches, and to have close games.

The first wish was answered, when RCB set a target of 206. I wonder if there were some kind of instructions from “big brother” instructing that the game go into the last over, as a means to increase flagging TRPs. If Vinay had bowled the 19th and gone for 10 (say), that would have left a near-impossible 33 off Kohli/Bhatkal’s over. Match over by over 19. One more match that is not “close”, which will do nothing to boost TRPs. But keep the contest alive till the last over, TRPs would be boosted?

As an RCB fan, I hereby call for the immediate sacking of Daniel Vettori as captain and his replacement at the helm by one of Kohli or AB De Villiers  (maybe even Vinay Kumar or Zaheer Khan). Maybe I should create an online signature campaign for this purpose, and use my contacts to get the results through to Anil Kumble and other powers-that-are at RCB.

 

When will my courier reach?

Earlier today, I had to urgently send a package to Mumbai. I was recommended that I use Bleudart since they guarantee next day delivery, and off I went to the Bluedart collection centre near my house. There, I learnt that there were 3 options.

For two hundred and eighty rupees (what I ultimately picked) I was guaranteed that the package would be delivered tomorrow. However, there were two premium offerings – promising 1030 am delivery, and 12 noon delivery. Given my payoffs I settled for the “normal” next day package. Now, I wonder when my package will reach.

What are the odds that the package would reach before noon? I would say the odds are very slim, for if my “normal” package were to reach before noon, there would be no reason for me in the future for me to pick the 1030 delivery or 12 delivery package. Even if the package would have reached close to the destination tomorrow morning (I expect that it’ll be sent on a late evening flight today or early morning flight tomorrow), the delivery person would be instructed to wait till after noon before delivering, I think.

What do you think? If you think it’ll reach before noon, you can bet on it. Leave a comment and we can discuss odds. I’ll give you the airwaybill number so we know when exactly it got delivered.

Update

I win the non-existent bet.

Pickup Date 12 October 2011
From Bangalore
To Mumbai
Status SHIPMENT DELIVERED 
Date of Delivery 13 October 2011
Time of Delivery 12:15


The Benjarong Conference

According to the Hindu calendar, today is the first anniversary of the Benjarong Conference. The said conference took place at Benjarong, an awesome Thai place on Ulsoor Road in Bangalore on the second day (dwitiya) of shukla paksha of Chaitra maasa of whatever samvatsara finished two days ago. The main topic discussed at the conference was arranged scissors and considering how things are now, I must say that the conference was indeed a success.

The occasion was a long weekend that also included Ugadi. Monkee and I (I lived in Gurgaon then) were both down in Bangalore for a weekend of bridehunting, and both of us hadn’t been having much luck in the market. Giving us gyaan on how to go about the arranged scissors process was K, who had just gotten arranged married, and Mukka who had just gotten love married. Also present with (as usual) lots of general fundaes in life were Kodhi and Harithekid.

Back during the conference, I had been entrusted with the job of noting down minutes of the meeting and blogging them; however I didn’t have net access back then in Bangalore and by the time I got back to the Gaon I got busy in other things and so here I am a full year late trying to share with the world things discussed at this great conference.

So here we were, two twenty six year old (maybe Monkee was still twenty five then) guys who had never had girlfriends wondering where and how people would fall in love, and where we could find interesting and single girls (yeah we did talk about the Goalkeeper Theory also). We chatted about various kinds of girls, where each type would find boys, the odds of each type being currently available for marriage, what parameters for search to put in matrimonial websites to maximize our odds of finding good girls, and the like.

One specific kind of girl that we spent a lot of time discussing was what K called as “township girl” – girls who grow up in PSU townships. He proposed that girls who grow up in PSU townships are more likely to be smart and liberal compared to girls of comparable family background and intelligence who don’t grow up in townships. This theory was largely seconded by a lot of others at the conference and I passed on it since I didn’t have a clue.

As alternatives to this, I had proposed the non-home-state theory claiming that girls who grow up otuside their home states are smarter and more liberal. The others supported this claiming that girls who have less contact with relatives and family-social engagements are likely to be more “outgoing”.

Then there was this puzzle about boys-majority colleges which a number of us had independently wondered about. If you notice, a large number of the more preferred colleges in India have an overwhelming boys majority (yeah this applies especially to engineering but considering that engineering is one of the most preferred undergraduate disciplines I suppose this assumption isn’t too wrong) and so any girl who goes to any of these colleges is extremely unlikely to land up in the arranged scissors market.

And then, if you would notice, in high school (10th board exams), distribution of marks of boys and girls is roughly equal. So the question is about where the smart girls go! Especially in cities like Bangalore and Madras which lack quality arts (a course which is usually dominated by girls) colleges. We had probably closed the conference promising to investigate this mystery – of where all the smart girls go.

I don’t remember too much about the food at Benjarong that day but I remember we had an extremely overbearing captain who kept coming to us every minute asking us how the food was. We followed our dinner at Benjarong with ice-cream at Corner house – excellent as usual. That is probably the last time I ate a full cake fudge.

A lot of questions raised at that conference are now probably moot, considering that both Monkee and I are on the roads to our respective marriages (he in May, me in November). However, I do need to apologize for taking one whole year to make and publicize these notes. My apologies to the general public for holding back such awesome thoughts from them for one whole year. And my thanks to Harithekid, Kodhi, Mukka, K and Monkee for making the Benjarong Conference possible.

Update

Another issue that was raised at the conference was about the fate of this blog after I find a long-term gene-propagating partner. The other attendees were all of the opinion that I will need to stop blogging after I find someone, or at least not blog on relationship-related topics.

A couple of weeks back,  Pinky shouted at me for NOT blogging enough about her.

Why Kannadigas are Inherently Lazy

There is something about the weather in Bangalore. There is something about the weather in Bangalore that perks you up. There is something about the weather in Bangalore that most of the time you really want to do something, to be active, to go out, walk around, lead an active life and all such. The first few days I spent in Bangalore after my return from Gurgaon in June I spent literally jumping around. The weather was so uplifting. It filled me with so much enthu for everything in life!

So I was wondering why people usually classify Kannadigas as being inherently lazy. As one of the professors in my JEE coaching factory used to say “naavu Kannadigarige aambode mosaranna koTTbiTTre khushhyaagiddbiDtivi” (if someone gives us Kannadigas dal vada and curd rice, we’ll live happily forever, and we will forget about working hard). Basically implying that we are inherently not too ambitious, and that we are generally laidback about stuff.

Thinking about it, I was wondering if the wonderful climate of South Interior Karnataka has to do with this (people from North Karnataka and the coast are supposed to be fairly hardworking, and are not known for their laidbackness unlike us Old Mysore people). I wonder if this laidbackness is because our wonderful weather has spoilt us. Spoilt us to an extent that we don’t really need to normally fight against the odds.

So I was thinking about Gurgaon, the other place where I’ve recently lived in. Gurgaon has horrible climate. Maybe a total of one month in the year can be desccribed as “pleasant”. Most of the time it’s either too hot or too cold. Temperatures are extreme. When it rains the whole place floods up. If people in Gurgaon are happy it is in spite of the weather and because of it. And therein lies the reason why people from there are traditionally more hardworking than us people from Old Mysore.

Blessed with such wonderful climate, we don’t really need to fight the odds. If today is too hot, we can put off the job for another day when we’re sure it’ll be cooler. If it rains too much today, we know that it’s likely to be dry tomorrow and can thus postpone it. Essentially we don’t need to put too much fight. When the weather is good, we are all jumpy and enthu and do our work. Which allows us to wait and sit when the weather is bad.

The man in Gurgaon, or in Chennai, or even in Raichur, however, can’t afford that. The likelihood of him having a good day weatherwise sometime in the near future is so thin that there exists just no point for him to postpone his work thinking he’ll do it when he feels better. This means that he is culturally (rather, climatically) conditioned to work against the odds. To do stuff even when he doesn’t want to do it. To essentially put more fight. And so he avoids that “inherently lazy” tag which people like us have unfortunately got.

I’m reminded of the second case that we did in our Corporate Strategy course at IIMB, from which the main learning was that sometimes your biggest strengths can turn out to be your biggest weaknesses.

nODi swami, naaviruvudu heege.