There are budget tricks, and there are budget tricks.

Some governors go to enormous lengths and expense to improve the way their finances look. They sell highways or government buildings, delay worker paychecks or tax refunds, or concoct new and costly ways to borrow money.

This year, Gov. Andrew M. Cuomo is pulling a budget trick ... on a budget.

“We have gone from a $10 billion deficit to a $2 billion surplus in just three short years,” Mr. Cuomo, a Democrat seeking re-election in November, declared in his State of the State address this month.

Left unexplained was the source of that surplus.

Mr. Cuomo’s official financial plan shed a little light, but not much: A four-sentence footnote essentially says that the surplus will materialize if the governor persuades lawmakers to approve big cuts to planned increases in spending in future budgets. The “magic footnote,” as one analyst christened it, thus contains a multibillion-dollar caveat.

That has not stopped Mr. Cuomo from trumpeting the $2 billion surplus as a leading success of his time as governor — as if he had already achieved it. But New Yorkers will also have to wait awhile to see if the governor’s confidence proves warranted.