One player shouldn't make a huge difference on a football field. After all, at any one time, there are 10 other players out there.
Quarterbacks are an obvious exception to that rule since they handle the ball so often.
But the Steelers have found they are not the same team when they don't have Joe Haden on the field. Since signing him after he was released by Cleveland last August, the Steelers are 13-3-1 (.794 win percentage) when they have Haden in the lineup. Without him? They're 4-2 (.667).
The Steelers are finding that Haden, their ageless 29-year-old cornerback, is no average Joe.
"Joe, we're from the same area, growing up," said Sean Davis, who like Haden, grew up in the Maryland suburbs of Washington D.C. "Joe is a legend. I've always known about Joe. His high school tape was legendary. I was always a big Joe Haden fan. When he came to us, it was like a dream come true. There's been nothing but good things with Joe."
While some of the Steelers' record with and without Haden could be considered a coincidence, there is no doubt that their defense is better with him on the field.
In the five games he missed in 2017 with a fractured fibula, the Steelers allowed 10 plays of 30 or more passing yards. They have given up eight such plays in 2018, with three coming in the one game -- Kansas City -- Haden missed with a hamstring injury.
More importantly, when the Steelers have had Haden in the lineup, they've allowed 18.1 points per game, including 21.6 this season. Without him the past two seasons, they've given up 28.7 points per game, including 42 on six touchdown passes in the loss to the Chiefs.
The Steelers might have an issue at the starting cornerback spot opposite Haden with Artie Burns struggling and sharing time with Coty Sensabaugh -- who missed Wednesday's practice with a toe injury -- but they have no issues with Haden.
"He's all about character," Marcus Gilbert, who also was Haden's teammate at Florida, told me. "There's a big difference when he's on the field and when he's not. The defense is completely different. With him in there, he changes our whole defense. He's an MVP-caliber player. When he's in there, you know he's going to get the job done. Guys are going to feed off of how he plays. The energy he brings, the excitement he brings, you just don't see from everybody."
Obviously, it's not all Haden. The Steelers were also missing Ryan Shazier when they beat Baltimore and lost to New England last December in two of the games Haden also was out.
However, there's no question the two-time Pro Bowl corner has been a stabilizing force in the Steelers' secondary.
"When I'm out there, I just do my job, keep the ball in front of me and try to make tackles," Haden said. "I'm communicating, making sure everybody's on the same page. I think my play helps. I'm trying to over-communicate and make sure everybody's on the same page."
Haden has done even more than just that. Of late, he's been matching up against the top receiving threat from the opposing team, helping to keep Atlanta's Julio Jones and Cincinnati's A.J. Green in check. Haden didn't follow a particular Cleveland receiver in last week's win over the Browns, but could do so this week against Baltimore's speedy John Brown when the Steelers (4-2-1) face the Ravens (4-4) Sunday at M&T Bank Stadium.
Brown had just three receptions for the Ravens in their 26-14 win in Pittsburgh in Week 4, but one was a 33-yard touchdown in the first quarter, while Brown also caught a 71-yard pass later in the game that didn't lead to a score because of a fumble.
When Haden is matched up one-on-one with a receiver, the Steelers don't have as many concerns those kind of plays will happen.
"I feel like when I'm back there as the post safety and there are multiple threats on the field, I can shade away from Joe and help other people because of the confidence I have in him," Davis told me. "It's a confidence we all have in him. We don't take that for granted."
That's why it was so strange when he was released by Cleveland last season after he refused to take a pay cut. Cleveland had plenty of cap space and had traded for quarterback Brock Osweiller in the offseason to not only acquire an extra second-round draft pick, but also to get up to the league-mandated salary floor.
Haden was a homegrown talent for the Browns, who had selected him seventh-overall in the 2010 draft, one of the few who had actually lived up to that potential in Cleveland. The Steelers immediately scooped him up, signing him to a three-year, $27-million contract.
"We want to thank Joe for all he has done for this organization both on and off the field," then-Browns executive vice president of football operations Sashi Brown said in a statement at the time when Haden was released. "He has been a great teammate and a true asset to the Cleveland community. These are very difficult decisions, we have the utmost respect for Joe and, in my eyes, he will always be a Cleveland Brown."
"Joe gave everything he had for the Cleveland Browns and that's all you can ask for as a coach," then-Browns coach Hue Jackson said in the statement. "He was a leader on and off the field. I wish him all the best as he continues his career."
Brown was fired last season -- perhaps in part for his release of Haden. Jackson was fired earlier this week after losing to the Steelers, 33-18, a game in which Haden recorded three tackles -- two of which were for a loss -- and an interception.
The Steelers, meanwhile, have reaped the benefits of having a veteran cornerback capable of matching up against the opposing team's best receiver, one handed to them on a silver platter.
"I can't," Gilbert told me when I asked if he could believe it when Cleveland released Haden. "I knew there was a good chance we'd pick him up. He knew all about the Steelers and the former (college teammates) we have on this team. It was familiar. He's a great football player and not only that, he's one of the best teammates I've ever had."