--As ballpark vendors say, you can't enjoy the game without a score card. Here is one for Tuesday night.

-- The election actually began four weeks ago, with early voting. Passion drives turnout; anger is a passion; contentment is not. Is there anger at incumbents generally, or only at Republican incumbents? Two years ago, 162 incumbents in each party (78 percent of Republicans re-elected and 87 percent of Democrats) won with at least 60 percent. Only 21 incumbents won with 55 percent or less. Will these numbers -- and the 98.6 re-election rate for incumbents since 1996 -- change dramatically? Stuart Rothenberg, an independent analyst, says that in the last 26 elections, dating to 1954, only three times (1956, 1990, 1992) have a total of at least six incumbents in each party lost.

-- Republicans Rob Simmons, Nancy Johnson and Chris Shays -- House members from Connecticut -- are vulnerable. If they lose, American politics will have become yet more "European," propelled by ideologically homogenous parties.

-- In the 14 presidential elections since 1952, only once (1964) did Democrats win more than 50 percent of the suburban vote. Last May, a Gallup Poll measured President Bush's approval among suburban voters at 29 percent. If Republicans are being rejected in suburbia, that will be apparent in two Pennsylvania districts, the 6th held by a second-term Republican, Jim Gerlach, and in the 7th held by Curt Weldon, vice chairman of the Armed Services Committee, now seeking an 11th term. Also watch the open seat contest -- the Republican incumbent is running for governor -- in Colorado's 7th, just north of Denver.

-- Florida's 22nd has one of the nation's best congressmen, Clay Shaw, who if Republicans retain control of the House will become chairman of the most consequential committee, Ways and Means. The 22nd has one of the nation's highest percentages of voters over the age of 65 -- 37 percent. In 2004, Shaw won with 63 percent but is in a close race, partly because many of his constituents are irritable because of their first encounter with the "doughnut hole" in Medicare's new prescription drug entitlement: The government pays 75 percent of the first $2,250 in annual drug expenditures, and 95 percent of expenditures over $5,100, but the individual must pay the cost between $2,250 and $5,100. Republicans hoped the new entitlement would purchase support from the elderly. If Shaw loses, that will be evidence for this axiom of politics in a welfare state: Any new entitlement generates less gratitude for what is given than it does resentment for what is withheld.

-- It is frequently said but infrequently true that Americans "vote their pocketbooks" -- that economic conditions determine their votes. In Michigan, however, economic determinism may prevail in the gubernatorial race, where Republican Dick DeVos is challenging Gov. Jennifer Granholm. The state has two Democratic senators and has voted Democratic in four consecutive presidential elections. But Michigan's unemployment rate, 7.1 percent, is far above the nation's 4.6 percent. Just three states are net losers of jobs in the last four years, and Michigan has lost the most. In August, a jobs fair in Sterling Heights, featuring factory jobs at $10 an hour and no benefits, drew 4,000 applicants. If DeVos, energetic and well-funded (partly by himself), cannot win, economic explanations of voting behavior should be interred.

-- Four years ago, all eight Mountain West states -- Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah and Wyoming -- had Republican governors. If Bill Ritter wins Colorado's governorship, Democrats will hold five of eight governorships in the Mountain West, which in the 1990s was even more reliably Republican than the South. In 2004, a change of a total of 63,508 votes in Colorado, Nevada and New Mexico would have given those states' 19 electoral votes and the presidency to John Kerry. No wonder the Democrats' 2008 convention will probably be in Denver.

-- Republicans will convene in Minneapolis, the largest city in "Minnewisowa." That neologism refers to the contiguous states of Minnesota, Wisconsin and Iowa, which have 27 electoral votes. Pollster Peter Hart notes that every president elected since 1912 has won a plurality of the states along the Mississippi River. Illinois is the only one of those 10 states that is reliably Democratic. In 2004, Iowa, one of just three states to switch sides from 2000 (with New Hampshire and New Mexico), went for Bush. John Kerry narrowly won Wisconsin and Minnesota with 49.7 percent and 51.1 percent respectively. If Minnesota's Republican Gov. Tim Pawlenty is re-elected, he goes on every Republican presidential candidate's shortlist of possible running mates.

There. A score card. Now, as ticket-takers say at ballpark turnstiles, enjoy the game.