Primaries show the danger of focusing on bad data

Whatever your politics, this year's presidential primaries are a great lesson in how to focus on the wrong metrics. Because I'm hearing way too much chatter about how many states a candidate has won -- a data point that's all but meaningless.

Folks, Texas has 27 million people. Vermont has less than a million. "States" are not some sort of measurement unit that have the same value -- especially with complicated delegate-selection rules that can let a "loser" earn as many delegates as a winner. Counting up "state wins" for a candidate would be like Amazon focusing on total number of customers instead of how much those customers buy and which sales are most profitable.

Don't believe me? Donald Trump "won" Vermont last night, but got the same number of delegates as runner-up Kasich: 6. Marco Rubio "won" the Minnesota caucus, and the prize was 1 more delegate than second-place Ted Cruz. Cruz, meanwhile, won Texas -- and got 37 more delegates than the number-two finisher.

Each of those was a "win." Are they all the same?

No.

The number of delegates at stake in each state is critical, but so is how they're handed out -- and, sometimes, margin of victory and how that margin's distributed. A candidate who wins a large state by a lot (or by a little if it's winner-take-all) picks up a lot more than one who barely wins a state where delegates get split.

And, of course, winning big in a large state means more than sweeping a tiny one.

Calculating the true value of a win in the Republican primary is complex this year because there are more than two candidates, which means the level of third place can also matter, not just runner-up. But let's leave that aside for now and just look at the delegate value of a win vs. the second-place finisher.

Below is a table of each state's results so far and what a "win" has meant for Republican candidates compared with the runner-up. (Caution: With all returns not yet in and some very complex delegate-award rules, this may change a bit.) So far, South Carolina was the top prize with Donald Trump sweeping all 50 delegates:

The Democratic primary is more straightforward because there are only two major candidates competing:

Something else to keep in mind if either race stays close through mid-spring: The biggest prize of all, California with 172 Republican delegates and 546 Democratic delegates, doesn't vote until June 7.