The Basketball Kama Sutra

Analytics Reveal 13 New Basketball Positions

For as long as basketball has been played, it’s been played with five positions. Today they are point guard, shooting guard, small forward, power forward and center. A California data geek sees 13 more hidden among them, with the power to help even the Charlotte Bobcats improve their lineup and win more games.

I think it has been long recognized that within any position you can have more of an offensive/defensive prowess, and that there are hybrid positions, regardless of what label you put on them. I’m also not close to being sold on NBA 1st team/2nd team, role-player or one-of-a-kind being a position. (Hey, I’m won the starting job at NBA All-Star on my team!) I think these are ways of categorizing the productivity of players, i.e their roles, rather than defining the position they play. You need a player or players with ball-handling skills, you need ball distribution, you need rebounding, you need scoring ability (interior and perimeter and also free throws), you need defense. How you divvy up those needed skills isn’t fixed, though some pairings might work better than others. This breakdown seems to imply that good players excel at a couple of skills (and the best at even more), or are somewhat less adept at each but possess a wider range of skills, and those pairings/groupings are given.

Now what would be really interesting would be looking at the depth and breadth of coverage of these roles as a function of the teams’ success. The diversity and output of the Mavericks that is shown — does that represent their success as well? Would a cellar-dwellar have the same breadth but simply be at a lower level of achievement, or do they suffer from not having some skill-set combination (e.g. single-skill players, rather than dual-skill), or both?

Oh, That Pesky Factor of Two

Venus to Appear in Once-In-A-Lifetime Event

On 5 and 6 June this year, millions of people around the world will be able to see Venus pass across the face of the Sun in what will be a once-in-a-lifetime experience.

Other than the fact that Venus made a transit in 2004; I got to see it and even got to see it with a telescope used in the 1874 and/or 1882 transit expeditions. So this is (for many of us; some people have been born since 2004) a twice-in-a-lifetime experience. However, if you missed the last one, this is it — you won’t get another chance until 2117. In the US, the sunset will interrupt the transit. For much of South America or western Africa (or anywhere in Antarctica), you’ll miss out if you stay where you are. Looks like Iceland has a unique situation of having sunset interrupt the middle of the transit, but will see at again at sunrise.

More information at Transit of Venus dot org.

Are You Getting Enough Fiber in Your Timing Diet?

I saw this paper last week and I might have gotten around to doing a blog post, but for reading Chad’s book, so he beat me to it. (OK: no, not really; I have to many other unfinished posts in the queue) Clock Synchronization Done Right: “A 920-Kilometer Optical Fiber Link for Frequency Metrology at the 19th Decimal Place”

OK, I admit, that’s a lot of zeroes. But why does that matter? Isn’t the whole point of ultra-precise atomic clocks that they all work exactly the same way? Why do you need to compare them? All atomic clocks using a given type of atom have the same basic frequency, but not all clocks are equally well made. The only way to determine the performance of a new one is to compare it to one you know works, but they’re also not very portable, so you need to be able to do the comparison remotely.

A nit: I wouldn’t necessarily characterize this as an issue of not being “equally well made”. One problem is that they are not identical — they are not the ideal clock used in thought experiments: there is noise, and it’s different for each clock. Each component in the clock can impact the clock in slightly different ways. But even if they were identical in all respects, you still have natural processes present in your oscillator, and these will give you white noise in the frequency of the clock. The integral of frequency give you the time, and the integral of white frequency noise is a random walk in phase, i.e. in the time. What does that mean? It means two clocks at identical frequencies will still undergo a random walk away from each other — they will lose synchronization. So you will still need to synchronize clocks, even if you could get them to the exact same frequency and remove all other kinds of noise. (Which you can’t).

Currently we are in a regime where clocks are better than time transfer techniques, at least over interesting distances. One can compare co-located clocks pretty well, but it doesn’t do anyone else any good if the precise time cannot be disseminated to them.