Help! Super Unlucky Fighter!

I run a small homebrew campaign for three of my friends. My best friend is the party's fighter, and lately, he's been feeling a little down because he feels like he doesn't have a lot of memorable, cool "hero" moments with his character. I wanted to change that! He's awesome, he deserves some hero moments! 
However... The problem is that while I *did* set these moments up, he's horribly unlucky. Every dice roll is just awful, the poor guy legit cannot roll above a 9. 

So... What do I do? 

I'm thinking of giving him an item or perhaps a blessing from a god, but what? I'm fresh out of ideas. 

If anyone can help, I'd appreciate it! 

It is hard to know what is going wrong without more details.  What type of check is he failing on?  Is he not using his class features? Indomitable, which is designed specifically for this kind of situation, immediately comes to mind.  Action Surge ans well, which immediately makes a turn feel more heroic.  Are you calling for checks that do not need to be called?  Generally, you should only call for a check if there’s a chance of failure.  Are they upset about the situation? Or are you reading too much into it, and finding a problem your player does not?  Are you failing in your encounter design?  Fighters are the Energizer Bunny of characters - they are designed to keep going when everyone else is out of resources.  If you are not taxing your other players’ resources enough, the fighter will never come to shine.

Bad luck is rarely a problem in its own.  It usually becomes more noticeable when either the player or DM (or both) is dropping the ball in other ways.

Also, you should not deus ex machina a solution to their problems.  That feels both like DM overreach and pity, as well as can make other players upset that your best friend is getting special treatment.  Figure out what the problems are other than bad luck and work to address those instead of hand waving a “solution.”

There's a few options of things you can do, but you do need to be careful about not playing favourites.

1) Add more ways for the players to get Heroic Inspiration to counteract bad dice rolls. I sometimes do this just for players flavouring their attacks, or simply attempting something heroic gets the Heroic Inspiration they can use on it. 

2) Give out some consumables or once per day magic items to the party. 

3) Allow him to do some things without rolling for them. You don't need to roll for everything, easy things, impossible things, or even things just so creative and cool you want them to just work, just allow them to do so. 

I wouldn't worry too much about making set-pieces for a specific character. It's one thing to do storylines that relate to a specific character (your contact turns out to be a banished member of the dwarf party member's clan, a powerful relic is hidden in a grove protected by the druid's people, etc). But specific cool/hero moments are tough to schedule. It's pretty easy to instead find yourself just kind of running the game in favor of one player. If you start setting up the fighter for awesome moments, start giving him blessings and items, pretty soon you're going to have to do that for the rest of the party too, or else they'll all feel left out. It can be a vicious cycle. More importantly, setting these things up for one character starts taking away elements of player choice. Your players feel heroic when they make heroic choices, and you can't really schedule that. It's up to them. 

Instead, I generally find that the better plan is to just make sure the game and encounters are dangerous and challenging overall. From there, let the party sort it out among themselves. There's where I would start. Can you up the challenge? Since the issue is with your fighter, I might start particularly by looking at your combats. Are the fights challenging and fast-paced enough to give the fighter room to shine? Are the monsters dangerous enough that your party members need the fighter standing between them and otherwise certain doom? That might resolve the issue entirely on its own. One place to start is The Monsters Know What They're Doing, a great site with lots of good ideas for improving combat if you need it. 

Beyond that, I might suggest the opposite of your current plan. Instead of giving the fighter a cool item or a blessing, give him a cursed item or a hex. It seems counterintuitive, but adventures are more epic when they're about solving problems and overcoming a challenge. Getting cool stuff is neat, but having three days to strike off a pair of cursed bracers before they infect you with lycanthropy is a story. 

I'd also look at the player's play style. This might be an issue for table talk and coaching. How creative and active is he outside of combat? How aggressive is he in combat? When he acts, either in combat or outside of it, does he get into character? How often does he act like his character would? Is he familiar with all his class features, or does he just swing the sword a bunch of times? If you can find patterns, you can always talk to him before the game starts to suggest ways he might have more fun. I.e. "do you know your character can do x, y, z" or "do you want to speak up more, how can we help you feel more involved." Out of combat, I've found it's effective to specifically prompt someone for their input in a specific situation or ask them what their character would do right now. In combat, encourage them to narrate their actions. Ask what they do and how they do it, to help this feel less like "I rolled an 18" and more like "I bashed it with my shield then, while it was dazed, stabbed it in the side."

And as to the numbers... that's a pain, but it will resolve itself. Most of the time this is just confirmation bias, and we see the numbers we expect to see. Sometimes players really do hit hot streaks or slumps. My players took down an epic ghost they had no business defeating because for one evening it seemed none of them could roll below a 20. They were supposed to either not pick that fight or, if they did, retreat back across the seance circle I placed in easy range. But, these things happen. 

Hope it helps!