The Philadelphia Marathon course

Out of the Parkway past the Cathedral Basilica, around Logan Circle and onto Arch Street. Wide, flat, and fueled entirely by adrenaline: whatever pace this mile hands you for free, do not go looking for more of it.

Arch Street into Old City, a jog north on 4th, then east on Race. Level ground and tight blocks, so run the tangents instead of fighting for space.

Race Street drops you onto Columbus Boulevard and the Delaware waterfront. Flat and wide open: if there is any wind today, this is where you meet it.

Columbus Boulevard south to Front Street and the turn onto Washington Avenue. Nothing here is steep and nothing here is hard, which makes it the right place to confirm your effort still feels boring.

South Street, 6th, and Front carry you back toward the historic core. Level ground and early miles: none of this should feel like work yet.

Chestnut Street at 6th puts you on Independence Hall's block. Flat pavement and plenty to look at, which is exactly why you should keep glancing at the watch instead.

Walnut Street runs west through Center City out to 15th. Level going, and the last of the downtown grid before the river.

The first real climb of the day: Walnut Street carries you over the Schuylkill and up into University City at 34th. Shorten the stride and give the split back willingly, because this is a preview of what mile 10 is going to ask for.

North on 34th Street, dead level the whole way. Spend it well, because it is the last flat road before Fairmount Park starts asking questions.

The Lansdowne Drive climb, the longest sustained rise on the course, running from just before 10 to just past 10.75. Pick a climbing effort you could repeat later and refuse to chase the pace you were running downtown.

Avenue of the Republic, States Drive, and Horticultural Drive through the west side of Fairmount Park. The climb finally tops out partway through the mile and the road settles, so use the level ground to get your breathing back.

Memorial Hall, now the Please Touch Museum, then Belmont Avenue and Lansdowne Drive falling away beneath you. This is the free mile of the middle third: let the legs turn over and resist the urge to hammer it.

West Girard Avenue and 33rd Street, where the road starts climbing again and keeps at it past 13.7. At nine tenths of a percent it is shallow enough to ignore and long enough to matter, so you will hear it in your breathing before you see it in the split.

Halfway arrives on 33rd and Reservoir Drive with the grade still tilted up. Read the split as information rather than a verdict, because the back half of this course is shaped nothing like the front.

Edgley Drive and Reservoir Drive through the park, essentially level. A short breather between the long climb behind you and the long drop in front of you.

The big one: Reservoir Drive and Fountain Green Drive fall hard toward the river. Quick feet, light landings, no braking. How you run this mile decides how your quads feel at 22.

Kelly Drive picks you up at the bottom with the Schuylkill on your left. Flat, straight and rhythmic, which is either a gift or a trap depending on how honestly you ran the first half.

A second flat mile on Kelly Drive with nothing at all to react to. That is the point: hold the cadence, hold the line, let it pass.

The road lifts toward Ridge Avenue and Manayunk, the last real rise of the day. It is modest on paper and will not feel modest underfoot, so keep the effort steady and let the pace drift if it wants to.

Main Street and Ridge Avenue in Manayunk, the outbound leg of the far end. Level ground and a turnaround you can almost taste, which is the exact combination that talks you into spending what you should be saving.

The turnaround on Main Street, and the moment the course finally points home. Take the turn under control and give yourself a few strides to find the rhythm again before you decide anything.

Back out Ridge Avenue and onto Kelly Drive, the river on your right now. Flat road from here to the finish, and every mile of it looks like the one before.

Kelly Drive again, level and unbroken. There is no terrain left to hide behind, so the pace you hold from here is simply the pace you have.

Just over two to go, and the road offers you nothing to work with, good or bad. Pick something up ahead, run to it, then pick another.

Flat pavement along the river with the Art Museum somewhere in front of you. Stop doing math, hold the effort, keep the turnover honest.

Boathouse Row on your right and one last small rise toward the finish. Thirteen feet is nothing on fresh legs and everything on these, so drive the arms and let the Parkway pull you in.