Silver said he thought "we" had the team, then playing in the NLDS, at "a 35 percent chance or something" of winning the three series in a row it still needed, and that the figure was rising.

Judged as of 2016-10-11. The claim is that the forecast Silver refers to ("we", i.e. FiveThirtyEight's MLB odds) gave the team in question, which was then playing in the NLDS, about a 35% chance of winning the World Series, and that this chance was rising. Because of "or something", any figure from about 30% to 40% counts as matching. True: FiveThirtyEight's published MLB playoff odds around 2016-10-11 show that team's World Series probability at roughly 30–40%, and the figure was going up (it had risen from earlier in the playoffs or after the latest game). Mostly true: the figure is within that range but was flat rather than rising, or the figure is slightly outside it (about 27–30% or 40–43%) and rising. Mixed: the figure is in range but clearly falling, or it matches only for a different forecast or a different round of the playoffs. Mostly false: the figure is well off (e.g. 20–27% or 43–50%). False: the figure is far off (below 20% or above 50%), or FiveThirtyEight had no such forecast.

Set before the research began.

1. E1 Statistician Nate Silver Rains on Cubs Fans' Parade Ahead of Playoffs NBC Chicago · 7 October 2016

   “The Cubs have a 42 percent chance of making the World Series (the highest among National League teams), and they do have a 26 percent chance of winning the Fall Classic according to Silver’s Five Thirty Eight modeling”

2. E2 The MLB playoffs are perfect - The Utah Statesman The Utah Statesman · 4 October 2016

   “The Cubs have no weakness on their roster, which is why fivethirtyeight.com gives them a 26% chance to win the World Series.”

3. E3 Cubs' Chances Of Winning World Series Are More Than Twice That Of Any Other Team CBS News Chicago (CBS Broadcasting) · 1 September 2016

   “It's Sept. 1, and the Cubs' chances of winning the World Series are more than twice that of any other team in baseball, according to the experts at fivethirtyeight.com. The Cubs have a 23 percent chance of winning the championship, per the data that's based on 50,000 simulations.”

Independent reports put the Cubs' FiveThirtyEight World Series probability at 23% on Sept. 1 (E4) and 26% around the start of the playoffs on Oct. 4–7 (E1, E3). None of the evidence gives the forecast's figure on or near 2016-10-11, after the NLDS games had been played. So the evidence cannot show whether the published odds were about 30–40% at that point, or whether they were rising.