Someone is asked to write his birth year, the year of an important event in his life, his age, the number of years since the important event occurred—and then add these four numbers. The mentalist predicts the total, which will usually be the current year multiplied by two.

A version of this force, according to Martin Gardner in his Mathematics, Magic and Mystery, 1956, p. 161, was included by Al Baker in Al Baker's Complete Manuscript, 1923. Stewart James, in commenting on this, reported that the name of the trick in this manuscript was “Thought Foretold” (see The James File, Vol. Two, Allan Slaight, 2002, p. 2212. The Baker manuscript, said by Gardner to be rare, does not appear in the comprehensive Secret Ways of Al Baker, edited by Todd Karr, 2003, but the force does appear there under the reported title "Thought Foretold", p. 749, copied from the notebooks of Eugene Bulson and dated July 1923.

In Baker's description, he points out that “You can repeat in my method and the answer is different each time…” While not the only possible interpretation, the most likely one suggests that his method built on a preceding handling that always yielded the same total, as is the case with the usual four-figure handling that was recorded after Baker. In Baker's handling, the spectator writes down and sums only three numbers, not four. The absence of the spectator's age in the calculation creates different totals. The use of the spectator's age makes it possible to present the number force as a prediction, whereas Baker's method is presented as a divination. Because his version involves pencil reading, age estimation and a minor mental calculation, it is not automatic, as is the four-figure version of the force. But it is repeatable and resistant to analysis afterward. The question remains, was the four-figure version the basis of Baker's handling, or was it was a simplification of Baker's version?

Two years after Baker's method was made known, the force, in it simple four-figure form was marketed as “Buddhah Prophecy”, by Allan Lambie in The Linking Ring, Vol. 3 No. 3, Sep. 1925, p. 43, as a single-effect manuscript (see James, above). Del-Ardo (Walter G. Magnuson) also marketed it around the same time, calling it “Twentieth Century Prophecy”. Other knockoffs swiftly followed. Robert Nelson released it under the same title used by Del-Ardo, "Twentieth Century Prophecy", n.d.; B. L. Gilbert released it as "Oriental Prophecy", c. 1926; Doc Nixon (William J. Dixon) included it in The Nixon Ghost Manuscript, 1929; etc.

Paul Curry cleverly embellished the presentation of the Date Addition Force in a piece called “Padding” in his booklet Something Borrowed, Something New, 1941, n.p., turning the prediction into a telepathy effect in which it is implied that the mentalist receives each of the spectator's four numbers as well as their total.