Nice fish eastern shores.... broken leader eh! In my opinion, broken leaders are human error or sometime technical problems, sorry I’m not criticising you but if you're breaking off fish you're likely doing something wrong so I’m offering some advice that might help you land that next big one that grabs your fly.
As a guide I see guys break fish off and 95% of the time its human error and 5% technical error. Rarely but sometimes knots give out or you have a nick in the line or the line bunches up in the reel but in my opinion that’s less then 5% of the time... Myself and my customers land between 300 and 500 steelhead per season so those stats are based on a lot of trial and error and a crap load of fish. I've noticed that most guys that break off put way to much pressure on the fish and are often new to steelhead fishing.. In my opinion if you set your drag right on a quality reel with a good drag system you shouldn’t be breaking fish off, even huge steelhead... Those fish move darn fast and pull hard so a good drag setting just below the breaking point is what you need to fight and land fish consistently with no break offs. If your drag is to loose you risk the line bunching up in the reel on fast running fish and the line will then tighten and possibly break under tension.. Drag setting is important.
Here's a tip for you when fighting a fish, if you have a drag set just right when the fish takes off lower the rod and point it at him while he's pulling at full force, There's less friction in the guides if the rods pointed straight at him and that lets the drag do all the work and as the fish slows down, slowly lift the rod high again... this way you give the fish more when it's pulling hard and there's less pressure on the line and less breaking fish off...Also, try to minimise the amount of line hanging below the reel when doing your drift.. If you do have a lot of line below the reel when the fish hits, let the fish take lots of line through you fingers but don’t pull him, keep steady or light pressure on him and let him run or shake and while it's doing that put the loose line coming off the reel under your right hand pinkie finger and reel like a mad man to take up slack and get that fish on the reel, One hand is reeling the other hand is leting line out under the fingers while the fish is pulling.. once you get him on the reel let the drag do the job...By using the pinkie method you're less likely going to tangle the line or bunch up the line at your hand or in the reel.. it works, trust me...
Another bit of advice... not all tippets are rated properly so tippet strength could be your issue. When I owned my tackle shop guys would come in complaining about one line breaking and another being much stronger or better... An example of this is Drennan leader material, the Drennan 4lb test is .20mm diameter.. where as Frog Hairs tippet material is 8lb test at .20mm and Seagar is 6lb test at .20mm diameter. 3 different companies lines all at the same diameter but all at different pound test rating. In my opinion they are all about 8lb test regardless of what they claim...So,That means if you only buy your leader/tippet using the pound test rating on the package you'll likely be breaking off on a tippet like 4lb frog hair but doing just fine with 4lb Drennan. In my opinion the companies do this so there line seams stronger then the next guys.. So, in my opinion if you put 4lb Drennan in a pulling contest with 8lb frog hair both are .20mm they will likely both break at close to the same pound of pull, but the guy on the river thinks he's going to catch more fish using 4lb so that’s the better line in his mind.It all marketing... I now only buy my line based on diameter size, what pound test the package says is irrelevant. What’s important is the diameter.. For clear water steelhead I use Drennan 3lb which or .18mm diameter and for slightly off color or dirty water I use 4lb Drennan or .20mm diameter lines and I rarely break fish off... Regardless of the brand, look at the diameter when you but tippet.. I just happen to like Drennan because it's a 50 meter spool and is cheaper then buying 2 spools of another companies 25m spools. Also floroucarbon is much better for knot strength and better with niks and cuts...
Something else to consider is your knot.... Some knots are rated at 97% break strength, or 92%, some are at 80% and some at 100% knot strenght... so which one do you want to use? Based on tests a Trilene Knot and Polomar knot are about 100%... so is a triple surgeons knot..... something to consider.. I rarely break off fish and rarely have a knot fail....
Good luck on the next big one,, I hope my advice helps in landing a tank.