This weekend's Monaco Grand Prix is seen as a halo event, mainly due to its long history, glamor, and the demanding nature of the tight street circuit right on the shoreline of the wealthy principality. However, the tight nature makes overtaking very difficult, which can lead to boring races. F1 rules usually mandate that two different tire compounds are used during a race (Pirelli bring "soft", "medium" and "hard" tires to each race chosen from six different compounds to best suit the likely wear expected at the circuit), meaning at least one pit stop. At last year's race there was a bad crash on the first lap which brought out a red flag. Most of the field used their enforced time in the pits to fit hard tires which lasted until the end of the race (lower speeds a Monaco mean lower tire wear). The top ten cars finished in exactly the same order in which they started. You can see the highlights (I use the term loosely) of the race here.
To try to avoid a repeat of this, teams will still have to use two tire compounds during the race at Monaco, but they have to make at least two pit stops this year. Time will tell if this makes any difference.
Local driver and last year's winner, Ferrari's Charles Leclerc, has been fastest in the first two practice sessions, with the McLarens also looking quick.