Nate Silver went on to argue why his model -- which, in its polls-only version, puts the odds of Hillary Clinton winning at 64.7 percent -- is superior to those like the Huffington Pos. Nate Silver rages at Huffington Post editor in 14-part tweetstorm

It began with “This article is so fucking idiotic and irresponsible,” and got only somewhat more polite from there.

Nate Silver unloaded Saturday on the Huffington Post’s Ryan Grim, who accused the polling guru and founder of the prediction website fivethirtyeight.com of “changing the results of polls to fit where he thinks the polls truly are, rather than simply entering the poll numbers into his model and crunching them.”


Rather than taking a simple average -- like RealClearPolitics does -- Silver’s model weights polls by his team’s assessment of their quality, and also performs several “adjustments” to account for things like the partisan “lean” of a pollster or the trend lines across different polls.

According to Grim, however, Silver is “just guessing” and his “trend line adjustment” technique is “merely political punditry dressed up as sophisticated mathematical modeling.” Grim also noted that FiveThirtyEight’s model -- due to his adjustments -- shows Trump more likely than not to win Florida, while the Huffington Post’s calculates her victory there as more likely.

And that, apparently, enraged Silver, whose track record of correctly predicting elections -- and explaining how he does it in painstaking, but accessible detail -- has made him a celebrity whose very name is synonymous with the art of data-driven prognostication, and whose model is widely considered the gold standard in election forecasting.

After dropping his initial f-bomb, Silver went on to argue why his model -- which, in its polls-only version, puts the odds of Hillary Clinton winning the presidential race at 64.7 percent -- is superior to those like the Huffington Post, which rates her election a near-certainty, at 98.3 percent.

The reason we adjust polls for the national trend is because **that's what works best emperically**. It's not a subjective assumption. — Nate Silver (@NateSilver538) November 5, 2016

It's wrong to show Clinton with a 6-point lead (as per HuffPo) when **almost no national poll shows that**. Doesn't reflect the data. — Nate Silver (@NateSilver538) November 5, 2016

Every model makes assumptions but we actually test ours based on the evidence. Some of the other models are barley even empirical. — Nate Silver (@NateSilver538) November 5, 2016

There are also a gajillion ways to make a model overconfident, whereas it's pretty hard to make one overconfident. — Nate Silver (@NateSilver538) November 5, 2016

If you haven't carefully tested how errors are correlated between states, for example, your model will be way overconfident. — Nate Silver (@NateSilver538) November 5, 2016

Not just an issue in elections models. Failure to understand how risks are correlated is part of what led to the 2007/8 financial crisis. — Nate Silver (@NateSilver538) November 5, 2016

There's a reasonable range of disagreement. But a model showing Clinton at 98% or 99% is not defensible based on the empirical evidence. — Nate Silver (@NateSilver538) November 5, 2016

We constantly write about our assumptions and **provide evidence** for why we think they're the right ones. https://t.co/IhLKXdxGGK — Nate Silver (@NateSilver538) November 5, 2016

That's what makes a model a useful scientific & journalistic tool. It's a way to understand how elections work. Not just about the results. — Nate Silver (@NateSilver538) November 5, 2016

The problem is that we're doing this in a world where people—like @ryangrim—don't actually give a shit about evidence and proof. — Nate Silver (@NateSilver538) November 5, 2016

The philosophy behind 538 is: Prove it. Doesn't mean we can't be wrong (we're wrong all the time). But prove it. Don't be lazy. — Nate Silver (@NateSilver538) November 5, 2016

And especially don't be lazy when your untested assumptions happen to validate your partisan beliefs. — Nate Silver (@NateSilver538) November 5, 2016

When you go low, I go high 80% of the time, and knee you in the balls the other 20% of the time. — Nate Silver (@NateSilver538) November 5, 2016

The Huffington Post’s senior polling editor, Natalie Jackson, didn’t tweet out Grim’s article. Asked by another Twitter user if she thought Silver was calling out “you and your staff,” Jackson demurred.

“He is,” she wrote. “But I'm not going to get into it on Twitter. Details are published several times over. (on both models).”

Grim, after Silver’s tweetstorm, responded by updating his post, but without engaging with his arguments.

“We’ll have to wait and see what happens,” he wrote. “Maybe Silver will be right come Election Day ― Trump will win Florida, and we’ll all be in for a very long night. Or our forecast will be right, she’ll win the state by 5 or 6, and we can all turn in early.

“If he’s right, though, it was just a good guess ― a fortunate ‘trend line adjustment’ ― not a mathematical forecast. If you want to put your faith in the numbers, you can relax. She’s got this.”