A few years ago, I got a lump sum from the sale of an apartment building and dollar-cost-averaged into QQQQ, SPY, and MDY.

If I had just plunked it all in at once I would be ahead of the game.

As you note, just doing it is better 75% of the time.

You will drive yourself nuts trying to second guess exactly when to buy.

Note: I may just be lucky, but almost every investment I have made over the past few years has immediately lost money in the 2-3 days after I buy, but has then come back to be profitable.