Before he was confirmed to the Supreme Court in 2006, Chief Justice John Roberts described judges as umpires calling balls and strikes, without regard to who was pitching or hitting. But how impartial would an umpire be if one team could redefine the strike zone to suit their pitcher’s or batters’ skills?

That is one way of looking at the issue in last week’s decision by the Supreme Court in Kisor v. Wilkie, decided in favor of Vietnam veteran’s James Kisor bid to receive benefits for the post-traumatic stress disorder (PTSD) he suffers.

That’s a great outcome for Kisor. But the even better news is that the court’s decision bodes well in the ongoing project to rein in the regulatory state and subject federal bureaucrats to meaningful oversight.

The background: The U.S. Department of Veterans Affairs (VA) denied Kisor’s PTSD claim by changing the rules on him. He presented records that were “relevant” to his claim (i.e., showing his combat service), as the VA regulations require. But the VA “re-interpreted” the word “relevant” to exclude Kisor’s combat documents, and then conveniently concluded that without “relevant” records he wasn’t entitled to benefits.

Sadly, the lower federal courts let the VA get away with this thanks to a 1997 Supreme Court case called Auer v. Robbins. Under so-called Auer deference, courts must let agencies decide what their regulations mean, particularly when an agency chooses a legally suspect meaning.

In other words, Kisor threw a strike to win his case, but the VA turned it into a ball by changing the strike zone, and the federal court, acting as “umpire,” passively accepted the VA’s self-interested re-interpretation of the rules.

This gives the government a big finger on the scales of justice and harms individual liberty. Sticking with the baseball analogy, it allows the government to win games it should lose when the citizen pitches better.

Fortunately for Kisor, the Supreme Court took his case and ruled that the lower courts had to take another look at whether his combat records are “relevant” under the VA regulations. In doing so, the court held that the lower courts may not reflexively defer to agency claims about what their rules mean.

As Justice Brett Kavanaugh put it in his separate opinion, umpires have to interpret and apply the ground rules. They don’t let the manager of the Chicago Cubs tell them how to interpret the Wrigley Field ground rules.

Although the court did not overrule Auer entirely, as many (including four of the justices) argued it should, the justices did restrict when agency interpretations can bind the courts. Judges must first use all the tools of statutory construction to determine whether a regulation is clear in the first place. Where a regulation is not clear, the agency interpretation of it must be one of the reasonable alternatives to warrant judicial deference.

The agency must also use its expertise in the particular subject matter and make clear that an interpretation is binding on the public, before courts may defer to it. Ad hoc interpretations by low-level agency staff, and after-the-fact litigation positions, will no longer command judicial deference. And finally, courts are no longer to defer to agency interpretations that inflict “unfair surprise” on regulated parties.

That means no more changing the strike zone after the pitch has been thrown, and no more moving the foul pole after the home run ball hits it.

These are all excellent reforms, even if the result is that courts will still defer in limited circumstances. Countless Americans will now get a fairer hearing in their cases against federal agencies as a result of Kisor.

In other words, the field is fairer now than it was; the scales are more even.

Batter up — let’s play ball.

Tony Francois (@TonyFrancoisESQ) is a senior attorney with the Pacific Legal Foundation, a nonprofit public interest law firm.