Here are the nine levels of concentration (shamatha) in Buddhism:

1. Placing the mind: You can briefly focus on the meditation object but quickly lose it. Distracting thoughts are frequent[1][4].

2. Continuous placement: You can maintain focus on the object for about 5 minutes. Conceptual thoughts start to lessen[1][4].

3. Resetting the mind: You can quickly return to the object when distracted without having to seek it out again[1][4].

4. Close placement: You can maintain focus on the object for the entire session without breaking concentration, though gross dullness and excitement may still occur[1][4].

5. Taming the mind: You need to revivify the mind to overcome subtle dullness. Distractions arise but can't pull you away from the object[1][4].

6. Pacifying the mind: You become more aware of subtle obstacles and address them quickly through vigilance[1][4].

7. Complete pacification: Your mindfulness and alertness are complete. You can maintain balance without being upset by subtle dullness or excitement[1][4].

8. Single-pointedness: Very little effort is required to maintain uninterrupted focus for the entire session, though some effort is still needed[1][4].

9. Balanced placement: You can effortlessly maintain faultless concentration with equanimity. The mind has settled into its natural state[1][4].

These nine stages outline the progressive development of concentration, from initial struggles with distraction to effortless, unwavering focus. They provide a roadmap for practitioners to gauge their progress and understand what needs to be cultivated at each level to advance their meditation practice.

Citations:

[1] https://buddhajourney.net/nine-levels-of-meditation/

[2] https://www.dhammawiki.com/index.php/9_Jhanas

[3] https://enlightenmentthangka.com/blogs/thangka/nine-stages-of-samatha-meditation

[4] https://glorian.org/connect/blog/stages-of-meditative-concentration

[5] https://www.lionsroar.com/the-nine-stages-of-training-the-mind/