For the past 50 years, once you secured the top executive job in any of six states, you were guaranteed to have kept it.

No governor has lost a reelection bid in Vermont, Connecticut, Wyoming, Pennsylvania, North Carolina or Tennessee since 1963, according to a new analysis of 669 gubernatorial elections, conducted by Eric J. Ostermeier, a research associate at the University of Minnesota’s Humphrey School’s Center for the Study of Politics and Governance. One-fourth of governors lost reelection over that period. The only state excluded was Virginia, where governors can’t run for reelection.

Vermont and New Hampshire have held the most gubernatorial elections over that period, with 25 elections each, thanks to their two-year terms. In Vermont, each of the 18 governors who have run for reelection have won. Connecticut has had the longest streak without a reelection loss. Gov. John D. Lodge (D) was the last incumbent to lose reelection there, in 1954. (Tennessee’s streak was technically longer—stretching back to 1952—but the state had banned consecutive terms from 1953 to the lat-1970’s.)

In three states, the odds of winning reelection were 1 in 2. In Mississippi, half the governors who ran for reelection suceeded, while just 43 percent did in Alabama and only 38 percent did in Alaska.

Since 1963, 304 governors have won reelection while 102 did not.