A recent article in The Washington Post outlines “numbers that most retail investors have never heard of” to help explain why value investor Ted Aronson of AJO Partners decided to stop “fighting a losing battle against markets.”

Aronson closed AJO and returned $10 billion to investors after growing “increasingly dissatisfied with his investment performance,” the article explains, citing tow market indicators that he routinely included in his monthly reporting: The S&P Value Index and the S&P Growth Index.

The article notes, “After Aronson announced October 15 he’s closing AJO at the end of the year, I started looking more closely at the Value and Growth numbers (which are subsets of the S&P 500) and found something that helps explain why Aronson is calling it quits,” adding, “They have a real story to tell us.”

AJO data reflects that growth has outperformed value for “every period from three months to 45 years” and Value has underperformed the broader S&P 500 index over the same periods.

“This means that for the past 13 years, value-oriented investors and money managers…have faced daunting odds, while growth-oriented investors and managers have had the wind at their backs. That’s why many value managers are frustrated. And why many of their investors are frustrated too, and taking their money back,” the article argues.

The 13-year value drought, says Aronson, “made value investors look like idiots.” Even if the value tide is on the cusp of turning, he contends that it would have taken AJO five years to return to decent returns. “We’re willing to take one for the [value] team,” he said.